/* ============================================================
   MULTI-CLOUD PASS — DESIGN SYSTEM v1.0
   ============================================================
   Single source of truth for colours, typography, spacing,
   component styles, animations, and dark/light context rules.

   Every page must reference these tokens. No hardcoded hex
   values outside this file.
   ============================================================ */

/* ────────────────────────────────────────────────────────────
   0. FONT IMPORTS
   ──────────────────────────────────────────────────────────── */

/* Satoshi — self-hosted from /static/fonts/satoshi/ (Fontshare, free licence) */
@font-face {
  font-family: 'Satoshi';
  src: url('../fonts/satoshi/Satoshi-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Satoshi';
  src: url('../fonts/satoshi/Satoshi-Medium.woff2') format('woff2');
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Satoshi';
  src: url('../fonts/satoshi/Satoshi-Bold.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Satoshi';
  src: url('../fonts/satoshi/Satoshi-Black.woff2') format('woff2');
  font-weight: 900;
  font-style: normal;
  font-display: swap;
}

/* DM Sans + JetBrains Mono from Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400;1,9..40,500&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ────────────────────────────────────────────────────────────
   1. COLOUR PALETTE
   ──────────────────────────────────────────────────────────── */

:root {
  /* ── Brand Primary: Warm Coral ── */
  --color-primary-50:  #FEF2F0;
  --color-primary-100: #FDE0DB;
  --color-primary-200: #F9B8AD;
  --color-primary-300: #F18E7D;
  --color-primary-400: #E8704C;
  --color-primary-500: #E2604A;   /* ← Primary */
  --color-primary-600: #C94A35;
  --color-primary-700: #A33A2A;
  --color-primary-800: #7D2D21;
  --color-primary-900: #5A201A;

  /* ── Brand Secondary: Ocean Teal ── */
  --color-secondary-50:  #ECFDF8;
  --color-secondary-100: #D1FAF0;
  --color-secondary-200: #A5F3E1;
  --color-secondary-300: #6EE7CC;
  --color-secondary-400: #2DD4B0;
  --color-secondary-500: #14B8A6;  /* ← Secondary */
  --color-secondary-600: #0D9488;
  --color-secondary-700: #0F766E;
  --color-secondary-800: #115E59;
  --color-secondary-900: #134E48;

  /* ── Brand Tertiary: Warm Gold ── */
  --color-gold-50:  #FFFBEB;
  --color-gold-100: #FEF3C7;
  --color-gold-200: #FDE68A;
  --color-gold-300: #FCD34D;
  --color-gold-400: #F5BD2E;
  --color-gold-500: #E5A832;  /* ← Gold accent */
  --color-gold-600: #CA8A04;
  --color-gold-700: #A16207;
  --color-gold-800: #854D0E;
  --color-gold-900: #713F12;

  /* ── Cloud Platform Colours (brand-accurate) ── */
  --color-aws:        #FF9900;
  --color-aws-light:  #FFAD33;
  --color-aws-dark:   #EC7211;
  --color-aws-bg:     rgba(255, 153, 0, 0.08);
  --color-aws-bg-solid: #1C1A14;

  --color-azure:        #0078D4;
  --color-azure-light:  #2899F5;
  --color-azure-dark:   #005BA1;
  --color-azure-bg:     rgba(0, 120, 212, 0.08);
  --color-azure-bg-solid: #131A22;

  --color-gcp:        #4285F4;
  --color-gcp-green:  #34A853;
  --color-gcp-yellow: #FBBC04;
  --color-gcp-red:    #EA4335;
  --color-gcp-bg:     rgba(66, 133, 244, 0.08);
  --color-gcp-bg-solid: #141922;

  --color-oci:        #F80000;
  --color-oci-light:  #FF3333;
  --color-oci-dark:   #C50000;
  --color-oci-bg:     rgba(248, 0, 0, 0.08);
  --color-oci-bg-solid: #1C1414;

  /* ── Semantic Colours ── */
  --color-success-50:  #F0FDF4;
  --color-success-100: #DCFCE7;
  --color-success-200: #BBF7D0;
  --color-success-300: #86EFAC;
  --color-success-400: #4ADE80;
  --color-success-500: #22C55E;  /* Correct answer */
  --color-success-600: #16A34A;
  --color-success-700: #15803D;

  --color-error-50:  #FEF2F2;
  --color-error-100: #FEE2E2;
  --color-error-200: #FECACA;
  --color-error-300: #FCA5A5;
  --color-error-400: #F87171;
  --color-error-500: #EF4444;  /* Wrong answer */
  --color-error-600: #DC2626;
  --color-error-700: #B91C1C;

  --color-warning-50:  #FFFBEB;
  --color-warning-100: #FEF3C7;
  --color-warning-200: #FDE68A;
  --color-warning-300: #FCD34D;
  --color-warning-400: #FBBF24;
  --color-warning-500: #F59E0B;  /* Warning */
  --color-warning-600: #D97706;
  --color-warning-700: #B45309;

  --color-info-50:  #EFF6FF;
  --color-info-100: #DBEAFE;
  --color-info-200: #BFDBFE;
  --color-info-300: #93C5FD;
  --color-info-400: #60A5FA;
  --color-info-500: #3B82F6;  /* Info */
  --color-info-600: #2563EB;
  --color-info-700: #1D4ED8;

  /* ── Neutrals (warm undertone) ── */
  --color-neutral-0:   #FFFFFF;
  --color-neutral-50:  #FAF9F7;
  --color-neutral-100: #F2F0ED;
  --color-neutral-200: #E6E3DF;
  --color-neutral-300: #D4D0CB;
  --color-neutral-400: #A8A29E;
  --color-neutral-500: #78716C;
  --color-neutral-600: #57534E;
  --color-neutral-700: #44403C;
  --color-neutral-800: #292524;
  --color-neutral-900: #1C1917;

  /* ── Dark Context Backgrounds ── */
  --color-dark-base:     #0F1419;  /* Deepest background */
  --color-dark-raised:   #161B22;  /* Cards, panels */
  --color-dark-surface:  #1C2333;  /* Elevated surfaces */
  --color-dark-overlay:  #232B3A;  /* Overlays, hover states */
  --color-dark-border:   #2D3548;  /* Subtle borders */
  --color-dark-border-bright: #3D4A60;  /* More visible borders */

  /* ── Light Context Backgrounds ── */
  --color-light-base:    #FAF9F7;  /* Page background (warm off-white) */
  --color-light-raised:  #FFFFFF;  /* Cards */
  --color-light-surface: #F2F0ED;  /* Panels, sidebars */
  --color-light-overlay: #E6E3DF;  /* Hover states */
  --color-light-border:  #D4D0CB;  /* Borders */

  /* ── Text Colours ── */
  --text-dark-primary:    #ECEDEE;  /* High emphasis on dark */
  --text-dark-secondary:  #9BA1AB;  /* Medium emphasis on dark */
  --text-dark-tertiary:   #5E6773;  /* Low emphasis on dark */
  --text-dark-disabled:   #3D4550;

  --text-light-primary:   #1C1917;  /* High emphasis on light */
  --text-light-secondary: #57534E;  /* Medium emphasis on light */
  --text-light-tertiary:  #A8A29E;  /* Low emphasis on light */
  --text-light-disabled:  #D4D0CB;

  /* ── Difficulty Colours ── */
  --color-diff-foundational: #14B8A6;  /* Teal — approachable */
  --color-diff-intermediate: #E5A832;  /* Gold — challenging */
  --color-diff-advanced:     #E2604A;  /* Coral — serious */
  --color-diff-expert:       #A855F7;  /* Purple — elite */

  /* ── Domain Colours (exam domains) ── */
  --color-domain-1: #E2604A;  /* Coral */
  --color-domain-2: #14B8A6;  /* Teal */
  --color-domain-3: #3B82F6;  /* Blue */
  --color-domain-4: #E5A832;  /* Gold */
  --color-domain-5: #A855F7;  /* Purple */
  --color-domain-6: #EC4899;  /* Pink */


  /* ────────────────────────────────────────────────────────────
     2. TYPOGRAPHY
     ──────────────────────────────────────────────────────────── */

  --font-display: 'Satoshi', system-ui, sans-serif;
  --font-body:    'DM Sans', system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', monospace;

  /* ── Type Scale ── */
  --text-xs:   0.75rem;    /* 12px */
  --text-sm:   0.875rem;   /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg:   1.125rem;   /* 18px */
  --text-xl:   1.25rem;    /* 20px */
  --text-2xl:  1.5rem;     /* 24px */
  --text-3xl:  1.875rem;   /* 30px */
  --text-4xl:  2.25rem;    /* 36px */
  --text-5xl:  3rem;       /* 48px */
  --text-6xl:  3.75rem;    /* 60px */

  /* ── Line Heights ── */
  --leading-none:    1;
  --leading-tight:   1.2;
  --leading-snug:    1.35;
  --leading-normal:  1.5;
  --leading-relaxed: 1.625;
  --leading-loose:   2;

  /* ── Letter Spacing ── */
  --tracking-tighter: -0.04em;
  --tracking-tight:   -0.02em;
  --tracking-normal:   0em;
  --tracking-wide:     0.02em;
  --tracking-wider:    0.04em;
  --tracking-widest:   0.08em;

  /* ── Font Weights ── */
  --weight-regular:  400;
  --weight-medium:   500;
  --weight-semibold: 600;
  --weight-bold:     700;


  /* ────────────────────────────────────────────────────────────
     3. SPACING & LAYOUT
     ──────────────────────────────────────────────────────────── */

  /* ── 8px Base Grid ── */
  --space-0:    0;
  --space-1:    0.25rem;   /* 4px — half-step for fine adjustments */
  --space-2:    0.5rem;    /* 8px */
  --space-3:    0.75rem;   /* 12px */
  --space-4:    1rem;      /* 16px */
  --space-5:    1.25rem;   /* 20px */
  --space-6:    1.5rem;    /* 24px */
  --space-8:    2rem;      /* 32px */
  --space-10:   2.5rem;    /* 40px */
  --space-12:   3rem;      /* 48px */
  --space-16:   4rem;      /* 64px */
  --space-20:   5rem;      /* 80px */
  --space-24:   6rem;      /* 96px */
  --space-32:   8rem;      /* 128px */

  /* ── Content Widths ── */
  --width-narrow:  640px;
  --width-medium:  960px;
  --width-wide:    1200px;
  --width-full:    1440px;

  /* ── Border Radius ── */
  --radius-xs:    4px;
  --radius-sm:    6px;
  --radius-md:    8px;
  --radius-lg:    12px;
  --radius-xl:    16px;
  --radius-2xl:   24px;
  --radius-full:  9999px;

  /* ── Shadows (dark context) ── */
  --shadow-dark-sm:  0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-dark-md:  0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-dark-lg:  0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-dark-xl:  0 16px 48px rgba(0, 0, 0, 0.6);

  /* ── Shadows (light context) ── */
  --shadow-light-sm:  0 1px 3px rgba(28, 25, 23, 0.06), 0 1px 2px rgba(28, 25, 23, 0.04);
  --shadow-light-md:  0 4px 12px rgba(28, 25, 23, 0.08), 0 2px 4px rgba(28, 25, 23, 0.04);
  --shadow-light-lg:  0 12px 32px rgba(28, 25, 23, 0.12), 0 4px 8px rgba(28, 25, 23, 0.06);
  --shadow-light-xl:  0 24px 64px rgba(28, 25, 23, 0.16), 0 8px 16px rgba(28, 25, 23, 0.08);

  /* ── Shadow (glow / emphasis) ── */
  --glow-primary:   0 0 20px rgba(226, 96, 74, 0.3);
  --glow-secondary: 0 0 20px rgba(20, 184, 166, 0.3);
  --glow-gold:      0 0 20px rgba(229, 168, 50, 0.3);
  --glow-success:   0 0 20px rgba(34, 197, 94, 0.3);


  /* ────────────────────────────────────────────────────────────
     5. ANIMATION TOKENS
     ──────────────────────────────────────────────────────────── */

  /* ── Durations ── */
  --duration-instant:  75ms;
  --duration-fast:     150ms;
  --duration-normal:   250ms;
  --duration-slow:     400ms;
  --duration-slower:   600ms;
  --duration-slowest:  1000ms;

  /* ── Easing Curves ── */
  --ease-default:     cubic-bezier(0.4, 0, 0.2, 1);     /* General purpose */
  --ease-in:          cubic-bezier(0.4, 0, 1, 1);        /* Entering */
  --ease-out:         cubic-bezier(0, 0, 0.2, 1);        /* Exiting */
  --ease-in-out:      cubic-bezier(0.4, 0, 0.2, 1);     /* Symmetric */
  --ease-bounce:      cubic-bezier(0.34, 1.56, 0.64, 1); /* Playful overshoot */
  --ease-spring:      cubic-bezier(0.22, 1.2, 0.36, 1);  /* Subtle spring */

  /* ── Z-Index Scale ── */
  --z-base:      0;
  --z-raised:    10;
  --z-dropdown:  100;
  --z-sticky:    200;
  --z-overlay:   300;
  --z-modal:     400;
  --z-toast:     500;
  --z-tooltip:   600;
}


/* ────────────────────────────────────────────────────────────
   4. COMPONENT STYLES
   ──────────────────────────────────────────────────────────── */

/* ── A. BUTTONS ── */

.ds-btn {
  font-family: var(--font-display);
  font-weight: var(--weight-semibold);
  font-size: var(--text-sm);
  letter-spacing: var(--tracking-wide);
  line-height: var(--leading-none);
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-6);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  transition: all var(--duration-fast) var(--ease-default);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.ds-btn:focus-visible {
  outline: 2px solid var(--color-secondary-500);
  outline-offset: 2px;
}

.ds-btn:active {
  transform: scale(0.97);
}

/* Primary Button — coral with light text */
.ds-btn-primary {
  background: var(--color-primary-500);
  color: #FFFFFF;
  border-color: var(--color-primary-500);
}
.ds-btn-primary:hover {
  background: var(--color-primary-600);
  border-color: var(--color-primary-600);
  box-shadow: var(--glow-primary);
}

/* Secondary Button — teal */
.ds-btn-secondary {
  background: var(--color-secondary-500);
  color: #FFFFFF;
  border-color: var(--color-secondary-500);
}
.ds-btn-secondary:hover {
  background: var(--color-secondary-600);
  border-color: var(--color-secondary-600);
  box-shadow: var(--glow-secondary);
}

/* Ghost Button — transparent with border */
.ds-btn-ghost {
  background: transparent;
  border-color: var(--color-dark-border-bright);
  color: var(--text-dark-primary);
}
.ds-btn-ghost:hover {
  background: var(--color-dark-overlay);
  border-color: var(--text-dark-secondary);
}

/* Ghost Light — for light backgrounds */
.ds-btn-ghost-light {
  background: transparent;
  border-color: var(--color-light-border);
  color: var(--text-light-primary);
}
.ds-btn-ghost-light:hover {
  background: var(--color-light-overlay);
  border-color: var(--text-light-secondary);
}

/* Gold / Achievement Button */
.ds-btn-gold {
  background: var(--color-gold-500);
  color: var(--color-neutral-900);
  border-color: var(--color-gold-500);
}
.ds-btn-gold:hover {
  background: var(--color-gold-400);
  box-shadow: var(--glow-gold);
}

/* Platform-Specific Buttons */
.ds-btn-aws {
  background: var(--color-aws);
  color: #FFFFFF;
  border-color: var(--color-aws);
}
.ds-btn-aws:hover {
  background: var(--color-aws-dark);
  box-shadow: 0 0 20px rgba(255, 153, 0, 0.3);
}

.ds-btn-azure {
  background: var(--color-azure);
  color: #FFFFFF;
  border-color: var(--color-azure);
}
.ds-btn-azure:hover {
  background: var(--color-azure-dark);
  box-shadow: 0 0 20px rgba(0, 120, 212, 0.3);
}

.ds-btn-gcp {
  background: var(--color-gcp);
  color: #FFFFFF;
  border-color: var(--color-gcp);
}
.ds-btn-gcp:hover {
  background: #3574DB;
  box-shadow: 0 0 20px rgba(66, 133, 244, 0.3);
}

.ds-btn-oci {
  background: var(--color-oci);
  color: #FFFFFF;
  border-color: var(--color-oci);
}
.ds-btn-oci:hover {
  background: var(--color-oci-dark);
  box-shadow: 0 0 20px rgba(248, 0, 0, 0.3);
}

/* Button Sizes */
.ds-btn-sm {
  font-size: var(--text-xs);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
}

.ds-btn-lg {
  font-size: var(--text-base);
  padding: var(--space-4) var(--space-8);
  border-radius: var(--radius-lg);
}

.ds-btn-xl {
  font-size: var(--text-lg);
  padding: var(--space-5) var(--space-10);
  border-radius: var(--radius-lg);
}


/* ── B. CARDS ── */

.ds-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform var(--duration-normal) var(--ease-spring),
              box-shadow var(--duration-normal) var(--ease-default);
}

/* Dark Card (default for scenario/diagram contexts) */
.ds-card-dark {
  background: var(--color-dark-raised);
  border: 1px solid var(--color-dark-border);
  box-shadow: var(--shadow-dark-sm);
}
.ds-card-dark:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-dark-md);
  border-color: var(--color-dark-border-bright);
}

/* Light Card (for info panels, pricing) */
.ds-card-light {
  background: var(--color-light-raised);
  border: 1px solid var(--color-light-border);
  box-shadow: var(--shadow-light-sm);
}
.ds-card-light:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-light-md);
}

/* Glass Card (frosted glass effect for overlays) */
.ds-card-glass {
  background: rgba(22, 27, 34, 0.7);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

/* Platform-tinted cards */
.ds-card-aws { border-left: 3px solid var(--color-aws); }
.ds-card-azure { border-left: 3px solid var(--color-azure); }
.ds-card-gcp { border-left: 3px solid var(--color-gcp); }
.ds-card-oci { border-left: 3px solid var(--color-oci); }

/* Scenario Card */
.ds-scenario-card {
  background: var(--color-dark-raised);
  border: 1px solid var(--color-dark-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-5);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-default);
}
.ds-scenario-card:hover {
  background: var(--color-dark-surface);
  border-color: var(--color-primary-500);
  box-shadow: inset 3px 0 0 var(--color-primary-500);
}
.ds-scenario-card.active {
  background: var(--color-dark-surface);
  border-color: var(--color-primary-500);
  box-shadow: inset 3px 0 0 var(--color-primary-500);
}

/* Quiz Card (for question display) */
.ds-quiz-card {
  background: var(--color-dark-raised);
  border: 1px solid var(--color-dark-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
}

/* Pricing Card */
.ds-pricing-card {
  background: var(--color-dark-raised);
  border: 2px solid var(--color-dark-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  text-align: center;
  transition: all var(--duration-normal) var(--ease-spring);
}
.ds-pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-dark-lg);
}
.ds-pricing-card.featured {
  border-color: var(--color-gold-500);
  box-shadow: var(--glow-gold);
}


/* ── C. BADGES & TAGS ── */

.ds-badge {
  font-family: var(--font-display);
  font-weight: var(--weight-semibold);
  font-size: var(--text-xs);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  line-height: var(--leading-none);
  white-space: nowrap;
}

/* Platform Badges */
.ds-badge-aws {
  background: rgba(255, 153, 0, 0.15);
  color: var(--color-aws-light);
  border: 1px solid rgba(255, 153, 0, 0.3);
}
.ds-badge-azure {
  background: rgba(0, 120, 212, 0.15);
  color: var(--color-azure-light);
  border: 1px solid rgba(0, 120, 212, 0.3);
}
.ds-badge-gcp {
  background: rgba(66, 133, 244, 0.15);
  color: #6EA8FF;
  border: 1px solid rgba(66, 133, 244, 0.3);
}
.ds-badge-oci {
  background: rgba(248, 0, 0, 0.15);
  color: var(--color-oci-light);
  border: 1px solid rgba(248, 0, 0, 0.3);
}

/* Difficulty Badges */
.ds-badge-foundational {
  background: rgba(20, 184, 166, 0.15);
  color: var(--color-secondary-400);
  border: 1px solid rgba(20, 184, 166, 0.3);
}
.ds-badge-intermediate {
  background: rgba(229, 168, 50, 0.15);
  color: var(--color-gold-400);
  border: 1px solid rgba(229, 168, 50, 0.3);
}
.ds-badge-advanced {
  background: rgba(226, 96, 74, 0.15);
  color: var(--color-primary-400);
  border: 1px solid rgba(226, 96, 74, 0.3);
}
.ds-badge-expert {
  background: rgba(168, 85, 247, 0.15);
  color: #C084FC;
  border: 1px solid rgba(168, 85, 247, 0.3);
}

/* Domain Tag */
.ds-tag {
  font-family: var(--font-body);
  font-weight: var(--weight-medium);
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  background: var(--color-dark-overlay);
  color: var(--text-dark-secondary);
  border: 1px solid var(--color-dark-border);
}

/* Achievement Badge */
.ds-badge-achievement {
  background: linear-gradient(135deg, var(--color-gold-500), var(--color-gold-400));
  color: var(--color-neutral-900);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-weight: var(--weight-bold);
  box-shadow: var(--glow-gold);
}


/* ── D. PROGRESS INDICATORS ── */

/* Linear Progress Bar */
.ds-progress {
  height: 8px;
  background: var(--color-dark-overlay);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.ds-progress-fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
  position: relative;
}

.ds-progress-fill-primary {
  background: linear-gradient(90deg, var(--color-primary-500), var(--color-primary-400));
}
.ds-progress-fill-secondary {
  background: linear-gradient(90deg, var(--color-secondary-500), var(--color-secondary-400));
}
.ds-progress-fill-gold {
  background: linear-gradient(90deg, var(--color-gold-600), var(--color-gold-400));
}
.ds-progress-fill-success {
  background: linear-gradient(90deg, var(--color-success-600), var(--color-success-400));
}

/* Animated shimmer on progress fill */
.ds-progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.15) 50%,
    transparent 100%
  );
  animation: ds-shimmer 2s infinite;
}

@keyframes ds-shimmer {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* Thin Progress Bar (for subtle contexts) */
.ds-progress-thin {
  height: 4px;
}

/* Circular Progress */
.ds-progress-circle {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.ds-progress-circle svg {
  transform: rotate(-90deg);
}
.ds-progress-circle-track {
  fill: none;
  stroke: var(--color-dark-overlay);
  stroke-width: 6;
}
.ds-progress-circle-fill {
  fill: none;
  stroke: var(--color-secondary-500);
  stroke-width: 6;
  stroke-linecap: round;
  transition: stroke-dashoffset var(--duration-slow) var(--ease-out);
}
.ds-progress-circle-label {
  position: absolute;
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  font-size: var(--text-lg);
  color: var(--text-dark-primary);
}

/* Streak Counter */
.ds-streak {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: rgba(229, 168, 50, 0.1);
  border: 1px solid rgba(229, 168, 50, 0.25);
  border-radius: var(--radius-full);
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  color: var(--color-gold-400);
}
.ds-streak-icon {
  font-size: var(--text-lg);
}


/* ── E. FORM ELEMENTS ── */

.ds-input {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  padding: var(--space-3) var(--space-4);
  background: var(--color-dark-base);
  border: 1px solid var(--color-dark-border);
  border-radius: var(--radius-md);
  color: var(--text-dark-primary);
  width: 100%;
  transition: border-color var(--duration-fast) var(--ease-default),
              box-shadow var(--duration-fast) var(--ease-default);
}
.ds-input:focus {
  outline: none;
  border-color: var(--color-secondary-500);
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.15);
}
.ds-input::placeholder {
  color: var(--text-dark-tertiary);
}

/* Light context input */
.ds-input-light {
  background: var(--color-light-raised);
  border-color: var(--color-light-border);
  color: var(--text-light-primary);
}
.ds-input-light:focus {
  border-color: var(--color-secondary-500);
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.1);
}

/* Select / Dropdown */
.ds-select {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  padding: var(--space-3) var(--space-8) var(--space-3) var(--space-4);
  background: var(--color-dark-base);
  border: 1px solid var(--color-dark-border);
  border-radius: var(--radius-md);
  color: var(--text-dark-primary);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%239BA1AB' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-3) center;
  cursor: pointer;
  transition: border-color var(--duration-fast) var(--ease-default);
}
.ds-select:focus {
  outline: none;
  border-color: var(--color-secondary-500);
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.15);
}

/* Toggle Switch */
.ds-toggle {
  position: relative;
  width: 44px;
  height: 24px;
  background: var(--color-dark-overlay);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: background var(--duration-fast) var(--ease-default);
  border: none;
  padding: 0;
}
.ds-toggle::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  background: var(--text-dark-primary);
  border-radius: 50%;
  transition: transform var(--duration-fast) var(--ease-bounce);
}
.ds-toggle.active {
  background: var(--color-secondary-500);
}
.ds-toggle.active::after {
  transform: translateX(20px);
}

/* Checkbox */
.ds-checkbox {
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-dark-border-bright);
  border-radius: var(--radius-xs);
  background: transparent;
  cursor: pointer;
  position: relative;
  transition: all var(--duration-fast) var(--ease-default);
}
.ds-checkbox.checked {
  background: var(--color-secondary-500);
  border-color: var(--color-secondary-500);
}
.ds-checkbox.checked::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 6px;
  width: 5px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* Radio Button */
.ds-radio {
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-dark-border-bright);
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
  position: relative;
  transition: all var(--duration-fast) var(--ease-default);
}
.ds-radio.checked {
  border-color: var(--color-secondary-500);
}
.ds-radio.checked::after {
  content: '';
  position: absolute;
  top: 4px;
  left: 4px;
  width: 8px;
  height: 8px;
  background: var(--color-secondary-500);
  border-radius: 50%;
}


/* ── F. NAVIGATION ── */

/* Top Nav Bar */
.ds-navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-6);
  background: rgba(15, 20, 25, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-dark-border);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
}

.ds-navbar-links {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.ds-nav-link {
  font-family: var(--font-body);
  font-weight: var(--weight-medium);
  font-size: var(--text-sm);
  color: var(--text-dark-secondary);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all var(--duration-fast) var(--ease-default);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}
.ds-nav-link:hover {
  color: var(--text-dark-primary);
  background: var(--color-dark-overlay);
}
.ds-nav-link.active {
  color: var(--color-primary-400);
  background: rgba(226, 96, 74, 0.1);
}

/* Platform Switcher (the AWS/Azure/GCP/OCI tabs in navbar) */
.ds-platform-switcher {
  display: flex;
  gap: var(--space-1);
  padding: var(--space-1);
  background: var(--color-dark-overlay);
  border-radius: var(--radius-md);
}
.ds-platform-tab {
  font-family: var(--font-display);
  font-weight: var(--weight-semibold);
  font-size: var(--text-xs);
  letter-spacing: var(--tracking-wide);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-default);
  color: var(--text-dark-secondary);
  background: transparent;
}
.ds-platform-tab:hover {
  color: var(--text-dark-primary);
}
.ds-platform-tab.active-aws   { background: var(--color-aws);   color: #fff; }
.ds-platform-tab.active-azure { background: var(--color-azure); color: #fff; }
.ds-platform-tab.active-gcp   { background: var(--color-gcp);   color: #fff; }
.ds-platform-tab.active-oci   { background: var(--color-oci);   color: #fff; }

/* Breadcrumbs */
.ds-breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--text-dark-tertiary);
}
.ds-breadcrumb a {
  color: var(--text-dark-secondary);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-default);
}
.ds-breadcrumb a:hover {
  color: var(--color-primary-400);
}
.ds-breadcrumb-separator {
  color: var(--text-dark-tertiary);
}

/* Tab Bar */
.ds-tabs {
  display: flex;
  gap: var(--space-1);
  border-bottom: 1px solid var(--color-dark-border);
  padding-bottom: 0;
}
.ds-tab {
  font-family: var(--font-body);
  font-weight: var(--weight-medium);
  font-size: var(--text-sm);
  color: var(--text-dark-secondary);
  padding: var(--space-3) var(--space-4);
  border: none;
  background: transparent;
  cursor: pointer;
  position: relative;
  transition: color var(--duration-fast) var(--ease-default);
}
.ds-tab:hover {
  color: var(--text-dark-primary);
}
.ds-tab.active {
  color: var(--color-primary-400);
}
.ds-tab.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-primary-500);
  border-radius: 2px 2px 0 0;
}


/* ── G. FEEDBACK STATES (Quiz-specific) ── */

/* Answer Option Button */
.ds-answer-option {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  text-align: left;
  padding: var(--space-4) var(--space-5);
  background: var(--color-dark-raised);
  border: 2px solid var(--color-dark-border);
  border-radius: var(--radius-lg);
  color: var(--text-dark-primary);
  cursor: pointer;
  width: 100%;
  transition: all var(--duration-fast) var(--ease-default);
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
}

.ds-answer-option:hover {
  border-color: var(--color-dark-border-bright);
  background: var(--color-dark-surface);
}

/* Selected (before submit) */
.ds-answer-option.selected {
  border-color: var(--color-secondary-500);
  background: rgba(20, 184, 166, 0.08);
}

/* Correct answer */
.ds-answer-option.correct {
  border-color: var(--color-success-500);
  background: rgba(34, 197, 94, 0.08);
  animation: ds-pulse-success var(--duration-slow) var(--ease-out);
}

/* Incorrect answer (the one user chose) */
.ds-answer-option.incorrect {
  border-color: var(--color-error-500);
  background: rgba(239, 68, 68, 0.08);
  animation: ds-shake var(--duration-normal) var(--ease-default);
}

/* Answer option letter badge (A, B, C, D) */
.ds-answer-letter {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  font-size: var(--text-sm);
  background: var(--color-dark-overlay);
  color: var(--text-dark-secondary);
  transition: all var(--duration-fast) var(--ease-default);
}
.ds-answer-option.selected .ds-answer-letter {
  background: var(--color-secondary-500);
  color: #fff;
}
.ds-answer-option.correct .ds-answer-letter {
  background: var(--color-success-500);
  color: #fff;
}
.ds-answer-option.incorrect .ds-answer-letter {
  background: var(--color-error-500);
  color: #fff;
}

/* Correct answer celebration */
@keyframes ds-pulse-success {
  0%   { box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.4); }
  50%  { box-shadow: 0 0 0 12px rgba(34, 197, 94, 0); }
  100% { box-shadow: 0 0 0 0 rgba(34, 197, 94, 0); }
}

/* Wrong answer shake */
@keyframes ds-shake {
  0%, 100% { transform: translateX(0); }
  20%      { transform: translateX(-6px); }
  40%      { transform: translateX(6px); }
  60%      { transform: translateX(-4px); }
  80%      { transform: translateX(4px); }
}

/* Explanation reveal panel */
.ds-explanation {
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  margin-top: var(--space-4);
  animation: ds-slide-up var(--duration-normal) var(--ease-out);
}
.ds-explanation-correct {
  background: rgba(34, 197, 94, 0.06);
  border: 1px solid rgba(34, 197, 94, 0.2);
}
.ds-explanation-incorrect {
  background: rgba(239, 68, 68, 0.06);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

/* Timer Display */
.ds-timer {
  font-family: var(--font-mono);
  font-weight: var(--weight-bold);
  font-size: var(--text-2xl);
  color: var(--text-dark-primary);
  padding: var(--space-2) var(--space-4);
  background: var(--color-dark-overlay);
  border-radius: var(--radius-md);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}
.ds-timer.warning {
  color: var(--color-warning-400);
  animation: ds-pulse-warn 1s infinite;
}
.ds-timer.critical {
  color: var(--color-error-400);
  animation: ds-pulse-warn 0.5s infinite;
}

@keyframes ds-pulse-warn {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.6; }
}

/* Score Summary */
.ds-score-ring {
  position: relative;
  width: 120px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.ds-score-ring-value {
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  font-size: var(--text-3xl);
  color: var(--text-dark-primary);
}
.ds-score-ring-label {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: var(--text-dark-secondary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
}

/* Loading Skeleton */
.ds-skeleton {
  background: linear-gradient(
    90deg,
    var(--color-dark-overlay) 25%,
    var(--color-dark-surface) 50%,
    var(--color-dark-overlay) 75%
  );
  background-size: 200% 100%;
  animation: ds-skeleton-pulse 1.5s infinite;
  border-radius: var(--radius-md);
}

@keyframes ds-skeleton-pulse {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* Empty State */
.ds-empty-state {
  text-align: center;
  padding: var(--space-16) var(--space-8);
  color: var(--text-dark-secondary);
}
.ds-empty-state-icon {
  font-size: var(--text-5xl);
  margin-bottom: var(--space-4);
  opacity: 0.4;
}
.ds-empty-state-title {
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  font-size: var(--text-xl);
  color: var(--text-dark-primary);
  margin-bottom: var(--space-2);
}


/* ────────────────────────────────────────────────────────────
   5b. ANIMATIONS & MICRO-INTERACTIONS
   ──────────────────────────────────────────────────────────── */

/* Slide up (for cards, panels appearing) */
@keyframes ds-slide-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Fade in */
@keyframes ds-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* Scale in (for modals, toasts) */
@keyframes ds-scale-in {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* Slide in from left (for sidebars) */
@keyframes ds-slide-in-left {
  from {
    opacity: 0;
    transform: translateX(-16px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Stagger children (apply to parent, children get sequential delay) */
.ds-stagger > * {
  animation: ds-slide-up var(--duration-normal) var(--ease-out) both;
}
.ds-stagger > *:nth-child(1)  { animation-delay: 0ms; }
.ds-stagger > *:nth-child(2)  { animation-delay: 50ms; }
.ds-stagger > *:nth-child(3)  { animation-delay: 100ms; }
.ds-stagger > *:nth-child(4)  { animation-delay: 150ms; }
.ds-stagger > *:nth-child(5)  { animation-delay: 200ms; }
.ds-stagger > *:nth-child(6)  { animation-delay: 250ms; }
.ds-stagger > *:nth-child(7)  { animation-delay: 300ms; }
.ds-stagger > *:nth-child(8)  { animation-delay: 350ms; }
.ds-stagger > *:nth-child(9)  { animation-delay: 400ms; }
.ds-stagger > *:nth-child(10) { animation-delay: 450ms; }

/* Achievement unlock celebration */
@keyframes ds-celebrate {
  0%   { transform: scale(0.5) rotate(-10deg); opacity: 0; }
  50%  { transform: scale(1.15) rotate(3deg); opacity: 1; }
  70%  { transform: scale(0.95) rotate(-1deg); }
  100% { transform: scale(1) rotate(0deg); opacity: 1; }
}

.ds-celebrate {
  animation: ds-celebrate var(--duration-slower) var(--ease-bounce);
}

/* Confetti burst (CSS-only, for correct answers / test completion) */
@keyframes ds-confetti-fall {
  0%   { transform: translateY(-100%) rotate(0deg); opacity: 1; }
  100% { transform: translateY(100vh) rotate(720deg); opacity: 0; }
}

.ds-confetti-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: var(--z-toast);
  overflow: hidden;
}

.ds-confetti-piece {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  animation: ds-confetti-fall 2.5s var(--ease-in) forwards;
}

/* Progress bar fill animation (for initial load) */
@keyframes ds-progress-fill {
  from { width: 0; }
}

.ds-progress-fill-animated {
  animation: ds-progress-fill var(--duration-slower) var(--ease-out);
}

/* Button ripple on click */
.ds-btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  transform: translate(-50%, -50%);
  transition: width var(--duration-slow) var(--ease-out),
              height var(--duration-slow) var(--ease-out),
              opacity var(--duration-slow) var(--ease-out);
  opacity: 0;
}
.ds-btn:active::before {
  width: 200%;
  height: 200%;
  opacity: 1;
  transition: 0s;
}

/* Number counter (for score reveals) */
@keyframes ds-count-up {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.ds-count-up {
  animation: ds-count-up var(--duration-normal) var(--ease-out);
}

/* Correct answer checkmark draw */
@keyframes ds-draw-check {
  0%   { stroke-dashoffset: 24; }
  100% { stroke-dashoffset: 0; }
}

.ds-checkmark {
  stroke-dasharray: 24;
  stroke-dashoffset: 24;
  animation: ds-draw-check var(--duration-normal) var(--ease-out) forwards;
  animation-delay: var(--duration-fast);
}


/* ────────────────────────────────────────────────────────────
   6. DARK / LIGHT CONTEXT RULES
   ──────────────────────────────────────────────────────────── */

/*
 * Dark context is the DEFAULT. Most pages use dark backgrounds.
 * Light context is applied via .ds-light-context on a container.
 *
 * WCAG AA contrast ratios:
 *   --text-dark-primary (#ECEDEE) on --color-dark-base (#0F1419) → 15.2:1 ✓
 *   --text-dark-secondary (#9BA1AB) on --color-dark-base (#0F1419) → 7.1:1 ✓
 *   --text-light-primary (#1C1917) on --color-light-base (#FAF9F7) → 16.8:1 ✓
 *   --text-light-secondary (#57534E) on --color-light-base (#FAF9F7) → 6.2:1 ✓
 */

/* Dark Context (default) */
.ds-dark-context,
[data-theme="dark"] {
  background-color: var(--color-dark-base);
  color: var(--text-dark-primary);
}

/* Light Context */
.ds-light-context,
[data-theme="light"] {
  background-color: var(--color-light-base);
  color: var(--text-light-primary);
}

/* Component overrides in light context */
.ds-light-context .ds-card {
  background: var(--color-light-raised);
  border-color: var(--color-light-border);
  box-shadow: var(--shadow-light-sm);
}
.ds-light-context .ds-card:hover {
  box-shadow: var(--shadow-light-md);
}

.ds-light-context .ds-input {
  background: var(--color-light-raised);
  border-color: var(--color-light-border);
  color: var(--text-light-primary);
}

.ds-light-context .ds-select {
  background-color: var(--color-light-raised);
  border-color: var(--color-light-border);
  color: var(--text-light-primary);
}

.ds-light-context .ds-btn-ghost {
  border-color: var(--color-light-border);
  color: var(--text-light-primary);
}
.ds-light-context .ds-btn-ghost:hover {
  background: var(--color-light-overlay);
}

.ds-light-context .ds-nav-link {
  color: var(--text-light-secondary);
}
.ds-light-context .ds-nav-link:hover {
  color: var(--text-light-primary);
  background: var(--color-light-overlay);
}

.ds-light-context .ds-progress {
  background: var(--color-light-overlay);
}

.ds-light-context .ds-answer-option {
  background: var(--color-light-raised);
  border-color: var(--color-light-border);
  color: var(--text-light-primary);
}
.ds-light-context .ds-answer-option:hover {
  background: var(--color-light-surface);
  border-color: var(--color-neutral-400);
}

.ds-light-context .ds-answer-letter {
  background: var(--color-light-overlay);
  color: var(--text-light-secondary);
}

.ds-light-context .ds-tag {
  background: var(--color-light-overlay);
  border-color: var(--color-light-border);
  color: var(--text-light-secondary);
}

.ds-light-context .ds-skeleton {
  background: linear-gradient(
    90deg,
    var(--color-light-overlay) 25%,
    var(--color-light-surface) 50%,
    var(--color-light-overlay) 75%
  );
  background-size: 200% 100%;
}

.ds-light-context .ds-timer {
  background: var(--color-light-overlay);
  color: var(--text-light-primary);
}


/* ────────────────────────────────────────────────────────────
   7. UTILITY CLASSES
   ──────────────────────────────────────────────────────────── */

/* Typography utilities */
.ds-font-display { font-family: var(--font-display); }
.ds-font-body    { font-family: var(--font-body); }
.ds-font-mono    { font-family: var(--font-mono); }

.ds-text-xs   { font-size: var(--text-xs); }
.ds-text-sm   { font-size: var(--text-sm); }
.ds-text-base { font-size: var(--text-base); }
.ds-text-lg   { font-size: var(--text-lg); }
.ds-text-xl   { font-size: var(--text-xl); }
.ds-text-2xl  { font-size: var(--text-2xl); }
.ds-text-3xl  { font-size: var(--text-3xl); }
.ds-text-4xl  { font-size: var(--text-4xl); }
.ds-text-5xl  { font-size: var(--text-5xl); }

.ds-font-regular  { font-weight: var(--weight-regular); }
.ds-font-medium   { font-weight: var(--weight-medium); }
.ds-font-semibold { font-weight: var(--weight-semibold); }
.ds-font-bold     { font-weight: var(--weight-bold); }

/* Colour utilities */
.ds-text-primary   { color: var(--color-primary-500); }
.ds-text-secondary { color: var(--color-secondary-500); }
.ds-text-gold      { color: var(--color-gold-500); }
.ds-text-success   { color: var(--color-success-500); }
.ds-text-error     { color: var(--color-error-500); }
.ds-text-warning   { color: var(--color-warning-500); }

.ds-text-muted     { color: var(--text-dark-secondary); }
.ds-text-faint     { color: var(--text-dark-tertiary); }

/* Platform text colours */
.ds-text-aws   { color: var(--color-aws); }
.ds-text-azure { color: var(--color-azure); }
.ds-text-gcp   { color: var(--color-gcp); }
.ds-text-oci   { color: var(--color-oci); }

/* Spacing utilities (key values only) */
.ds-p-4  { padding: var(--space-4); }
.ds-p-6  { padding: var(--space-6); }
.ds-p-8  { padding: var(--space-8); }
.ds-px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.ds-px-6 { padding-left: var(--space-6); padding-right: var(--space-6); }
.ds-py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.ds-py-8 { padding-top: var(--space-8); padding-bottom: var(--space-8); }

.ds-m-0   { margin: 0; }
.ds-mt-4  { margin-top: var(--space-4); }
.ds-mt-8  { margin-top: var(--space-8); }
.ds-mb-4  { margin-bottom: var(--space-4); }
.ds-mb-8  { margin-bottom: var(--space-8); }

.ds-gap-2 { gap: var(--space-2); }
.ds-gap-4 { gap: var(--space-4); }
.ds-gap-6 { gap: var(--space-6); }
.ds-gap-8 { gap: var(--space-8); }

/* Layout utilities */
.ds-flex       { display: flex; }
.ds-flex-col   { flex-direction: column; }
.ds-flex-wrap  { flex-wrap: wrap; }
.ds-items-center   { align-items: center; }
.ds-justify-center { justify-content: center; }
.ds-justify-between { justify-content: space-between; }

.ds-grid { display: grid; }
.ds-grid-2 { grid-template-columns: repeat(2, 1fr); }
.ds-grid-3 { grid-template-columns: repeat(3, 1fr); }
.ds-grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Content width containers */
.ds-container-narrow { max-width: var(--width-narrow); margin: 0 auto; padding: 0 var(--space-4); }
.ds-container-medium { max-width: var(--width-medium); margin: 0 auto; padding: 0 var(--space-4); }
.ds-container-wide   { max-width: var(--width-wide);   margin: 0 auto; padding: 0 var(--space-6); }
.ds-container-full   { max-width: var(--width-full);   margin: 0 auto; padding: 0 var(--space-6); }

/* Border utilities */
.ds-rounded-md  { border-radius: var(--radius-md); }
.ds-rounded-lg  { border-radius: var(--radius-lg); }
.ds-rounded-xl  { border-radius: var(--radius-xl); }
.ds-rounded-full { border-radius: var(--radius-full); }

/* Truncate text */
.ds-truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Visually hidden (for accessibility) */
.ds-sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}


/* ────────────────────────────────────────────────────────────
   8. RESPONSIVE BREAKPOINTS
   ──────────────────────────────────────────────────────────── */

/* Tablet and below */
@media (max-width: 768px) {
  :root {
    --text-4xl: 1.875rem;
    --text-5xl: 2.25rem;
    --text-6xl: 3rem;
  }

  .ds-grid-2 { grid-template-columns: 1fr; }
  .ds-grid-3 { grid-template-columns: 1fr; }
  .ds-grid-4 { grid-template-columns: repeat(2, 1fr); }

  .ds-container-wide,
  .ds-container-full {
    padding: 0 var(--space-4);
  }

  .ds-navbar {
    padding: var(--space-2) var(--space-4);
  }

  .ds-btn-xl {
    font-size: var(--text-base);
    padding: var(--space-4) var(--space-6);
  }
}

/* Mobile */
@media (max-width: 480px) {
  :root {
    --text-3xl: 1.5rem;
    --text-4xl: 1.75rem;
    --text-5xl: 2rem;
  }

  .ds-grid-4 { grid-template-columns: 1fr; }

  .ds-platform-switcher {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .ds-quiz-card {
    padding: var(--space-4);
  }

  .ds-answer-option {
    padding: var(--space-3) var(--space-4);
  }
}