/* ============================================================
   DESIGN SYSTEM — CSS VARIABLES
   Shriyansh GameDev Portfolio
============================================================ */
:root {
  /* Backgrounds */
  --bg-base:          #0f1419;
  --bg-deep:          #1a202c;
  --bg-surface:       rgba(31, 41, 55, 0.5);
  --bg-surface-heavy: rgba(31, 41, 55, 0.7);
  --bg-nav:           rgba(17, 24, 39, 0.95);
  --bg-nav-mobile:    rgba(17, 24, 39, 0.98);
  --bg-footer:        #111827;
  --bg-input:         rgba(31, 41, 55, 0.7);

  /* Primary — Blue */
  --color-primary:        #60a5fa;
  --color-primary-hover:  #93c5fd;
  --color-primary-dark:   #2563eb;
  --color-primary-10:     rgba(96, 165, 250, 0.10);
  --color-primary-20:     rgba(96, 165, 250, 0.20);
  --color-primary-30:     rgba(96, 165, 250, 0.30);
  --color-primary-40:     rgba(96, 165, 250, 0.40);
  --color-primary-50:     rgba(96, 165, 250, 0.50);

  /* Secondary — Plasma Pink (~337°, triadic partner to Blue at 213°) */
  --color-secondary:      #f0538e;
  --color-secondary-dark: #d4396e;
  --color-secondary-10:   rgba(240, 83, 142, 0.10);
  --color-secondary-40:   rgba(240, 83, 142, 0.40);

  /* Accent — Green */
  --color-accent:         #10b981;
  --color-accent-hover:   #059669;
  --color-accent-deep:    #047857;
  --color-accent-30:      rgba(16, 185, 129, 0.30);
  --color-accent-40:      rgba(16, 185, 129, 0.40);

  /* Semantic */
  --color-warning:        #f59e0b;
  --color-warning-10:     rgba(245, 158, 11, 0.10);
  --color-danger:         #dc2626;
  --color-danger-10:      rgba(220, 38, 38, 0.10);
  --color-error:          #ef4444;
  --color-error-08:       rgba(239, 68, 68, 0.08);
  --color-error-20:       rgba(239, 68, 68, 0.20);
  --color-orange:         #f97316;
  --color-pink:           #ec4899;
  --color-pink-10:        rgba(236, 72, 153, 0.10);
  --color-pink-30:        rgba(236, 72, 153, 0.30);

  /* Text */
  --text-bright:    #f9fafb;
  --text-primary:   #e2e8f0;
  --text-secondary: #d1d5db;
  --text-muted:     #9ca3af;
  --text-on-dark:   #ffffff;

  /* Borders */
  --border-input:   #4b5563;
  --border-primary: var(--color-primary);

  /* Gradients */
  --gradient-body:        linear-gradient(135deg, var(--bg-base), var(--bg-deep));
  --gradient-hero-bg:     linear-gradient(45deg, var(--color-primary-10), rgba(96, 165, 250, 0.04));
  --gradient-hero-radial: radial-gradient(circle, var(--color-primary-10) 0%, transparent 70%);
  --gradient-brand:       linear-gradient(135deg, var(--color-primary-hover), var(--color-primary-dark));
  --gradient-cta:         linear-gradient(135deg, #1d4ed8, var(--color-primary-dark));
  --gradient-accent:      linear-gradient(135deg, var(--color-accent), var(--color-accent-hover));
  --gradient-project-1:   linear-gradient(45deg, #374151, #4b5563);
  --gradient-gdd-1:       linear-gradient(135deg, #92400e, #431407);
  --gradient-gdd-2:       linear-gradient(135deg, #7f1d1d, #3b0707);
  --gradient-collab:      linear-gradient(135deg, #78350f, #431407);
  --gradient-aiml:        linear-gradient(135deg, var(--color-secondary), #ec4899);
  --gradient-collab-bg:   linear-gradient(135deg, var(--color-accent-30), var(--color-primary-10));
  --gradient-aiml-bg:     linear-gradient(135deg, var(--color-secondary-10), rgba(236, 72, 153, 0.10));

  /* Shadows */
  --shadow-nav:        0 2px 20px rgba(0, 0, 0, 0.30);
  --shadow-primary:    0 4px 15px var(--color-primary-30);
  --shadow-primary-lg: 0 6px 20px var(--color-primary-40);
  --shadow-accent:     0 4px 15px var(--color-accent-30);
  --shadow-accent-lg:  0 6px 20px var(--color-accent-40);
  --shadow-cta:        0 4px 15px var(--color-primary-30);
  --shadow-cta-lg:     0 6px 25px var(--color-primary-40);
  --shadow-profile:    0 8px 30px var(--color-primary-30);
  --shadow-aiml:       0 4px 15px var(--color-secondary-40);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;

  /* Radius */
  --radius-sm:   8px;
  --radius-md:   12px;
  --radius-lg:   15px;
  --radius-xl:   20px;
  --radius-full: 9999px;

  /* Transitions */
  --transition: 0.3s ease;
}

/* ============================================================
   RESET
============================================================ */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--gradient-body);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
  max-width: 1400px;
  margin-inline: auto;
}

img { max-width: 100%; display: block; }
ul  { list-style: none; }

/* ============================================================
   SKIP TO CONTENT — WCAG 2.4.1
============================================================ */
.skip-link {
  position: fixed;
  top: var(--space-4);
  left: var(--space-4);
  z-index: 9999;
  padding: 0.6rem 1.2rem;
  background: var(--color-primary);
  color: var(--bg-base);
  font-weight: 700;
  font-size: 0.9rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--transition);
  box-shadow: var(--shadow-primary-lg);
}

.skip-link:focus { transform: translateY(0); }

/* ============================================================
   TYPOGRAPHY
============================================================ */
h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); font-weight: 800; line-height: 1.15; }
h2 { font-size: clamp(1.8rem, 4vw, 2.5rem); font-weight: 700; color: var(--text-bright); }
h3 { font-size: 1.25rem; font-weight: 600; color: var(--text-bright); }
h4 { font-size: 1.05rem; font-weight: 600; }

p  { max-width: 70ch; line-height: 1.75; }

/* ============================================================
   FOCUS VISIBLE — WCAG 2.4.7
============================================================ */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   REDUCED MOTION — WCAG 2.3.3
============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============================================================
   BUTTONS
============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.7rem 1.5rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: all var(--transition);
  outline: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

.btn-primary {
  background: var(--gradient-cta);
  color: var(--text-on-dark);
  box-shadow: var(--shadow-cta);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-cta-lg);
}

.btn-primary:active { transform: translateY(0); }

.btn-accent {
  background: var(--gradient-accent);
  color: var(--text-on-dark);
  box-shadow: var(--shadow-accent);
}

.btn-accent:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-accent-lg);
}

.btn-accent:active { transform: translateY(0); }

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary-30);
}

.btn-outline:hover {
  background: var(--color-primary-10);
  border-color: var(--color-primary);
}

/* ============================================================
   LAYOUT
============================================================ */
.container {
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--space-8);
}

section.section {
  padding: 5.5rem var(--space-8);
  max-width: 1200px;
  margin: 0 auto;
  border-bottom: 1px solid rgba(96, 165, 250, 0.07);
}

section.section:last-of-type {
  border-bottom: none;
}

.section-title {
  text-align: center;
  margin-bottom: var(--space-12);
  position: relative;
  padding-bottom: var(--space-5);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 3rem;
  height: 3px;
  background: var(--gradient-brand);
  border-radius: var(--radius-full);
}

/* ============================================================
   NAVIGATION
============================================================ */
header {
  background: var(--bg-nav);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  padding: var(--space-4) 0;
  box-shadow: var(--shadow-nav);
  transition: padding var(--transition);
}

header.scrolled { padding: 0.6rem 0; }

nav {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 var(--space-8);
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-primary);
  text-decoration: none;
  letter-spacing: -0.02em;
  line-height: 1;
  flex-shrink: 0;
}

/* Groups mode-toggle + hamburger so space-between works correctly */
.nav-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--space-1);
  align-items: center;
}

.nav-links a {
  display: flex;
  align-items: center;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition), background var(--transition);
  padding: 0.5rem var(--space-4);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1;
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-primary);
  background: var(--color-primary-10);
}

.nav-links .resume-btn,
.nav-links .resume-btn:hover {
  color: var(--text-on-dark);
}

.resume-btn {
  background: var(--gradient-accent);
  color: var(--text-on-dark);
  padding: 0.5rem 1.2rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  line-height: 1;
  box-shadow: var(--shadow-accent);
}

.resume-btn:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-accent-lg);
}

/* Hamburger */
.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-sm);
}

.mobile-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: var(--radius-full);
  transition: transform var(--transition), opacity 0.2s ease;
}

.mobile-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-toggle.open span:nth-child(2) { opacity: 0; }
.mobile-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile drawer */
.mobile-drawer {
  display: none;
  position: fixed;
  top: 65px;
  left: 0;
  right: 0;
  background: var(--bg-nav-mobile);
  backdrop-filter: blur(10px);
  padding: var(--space-4) var(--space-8);
  flex-direction: column;
  gap: var(--space-2);
  border-bottom: 1px solid var(--color-primary-10);
  z-index: 999;
}

.mobile-drawer.open { display: flex; }

.mobile-drawer a {
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  font-weight: 500;
  transition: color var(--transition), background var(--transition);
}

.mobile-drawer a:hover {
  color: var(--color-primary);
  background: var(--color-primary-10);
}

/* ============================================================
   HERO
============================================================ */
main { margin-top: 72px; }

.hero {
  text-align: center;
  padding: 9rem var(--space-8);
  background: var(--gradient-hero-bg);
  border-radius: var(--radius-xl);
  margin: var(--space-8) auto;
  max-width: 1200px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: var(--gradient-hero-radial);
  animation: rotateBg 20s linear infinite;
  pointer-events: none;
}

@keyframes rotateBg {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin-inline: auto;
}

.hero h1 {
  margin-bottom: var(--space-4);
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: var(--space-8);
  color: var(--text-muted);
  margin-inline: auto;
}

/* ============================================================
   ABOUT
============================================================ */
.about-content {
  display: flex;
  align-items: center;
  gap: var(--space-12);
  flex-wrap: wrap;
}

.about-text {
  flex: 1;
  min-width: 300px;
}

.about-text p { color: var(--text-secondary); }

.about-image {
  flex: 0 0 250px;
  text-align: center;
}

.profile-avatar {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-on-dark);
  border: 4px solid var(--color-primary);
  box-shadow: var(--shadow-profile), 0 0 40px var(--color-primary-20);
  margin-inline: auto;
  overflow: hidden;
  text-shadow: 0 2px 8px rgba(0,0,0,0.3);
  user-select: none;
}

/* ============================================================
   SKILLS
============================================================ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.skill-card {
  background: var(--bg-surface);
  padding: var(--space-8);
  border-radius: var(--radius-lg);
  text-align: center;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
  border: 1px solid var(--color-primary-20);
}

.skill-card:hover {
  transform: translateY(-8px);
  border-color: var(--color-primary-50);
  box-shadow: 0 8px 30px var(--color-primary-20);
}

.skill-card:focus-within { border-color: var(--color-primary); }

.skill-icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-3);
  display: block;
  line-height: 1;
  filter: saturate(0.55) brightness(1.1);
}

.skill-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: var(--space-1);
}

.skill-card p {
  font-size: 0.78rem;
  color: var(--text-muted);
  line-height: 1.5;
  max-width: none;
}

/* ============================================================
   PROJECT CARDS
============================================================ */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-8);
  margin-bottom: var(--space-12);
}

.project-card {
  background: var(--bg-surface-heavy);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
  border: 1px solid var(--color-primary-20);
  display: flex;
  flex-direction: column;
  min-height: 420px;
}

.project-card:hover {
  transform: translateY(-8px);
  border-color: var(--color-primary-50);
  box-shadow: 0 12px 40px var(--color-primary-20);
}

.project-img {
  width: 100%;
  height: 170px;
  background: var(--gradient-project-1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 1.1rem;
  position: relative;
}

.project-content {
  padding: var(--space-6);
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.project-content p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  flex: 1;
}

.project-title {
  font-size: 1.3rem;
  color: var(--text-bright);
}

/* ============================================================
   CONTACT FORM
============================================================ */
.contact-form {
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.form-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
}

input,
textarea {
  width: 100%;
  padding: 0.85rem var(--space-4);
  background: var(--bg-input);
  border: 1.5px solid var(--border-input);
  border-radius: var(--radius-sm);
  color: var(--text-bright);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

input::placeholder,
textarea::placeholder { color: var(--text-muted); }

input:hover,
textarea:hover { border-color: var(--color-primary-30); }

input:focus,
textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-10);
}

textarea { resize: vertical; min-height: 140px; line-height: 1.6; }

/* Form error */
.form-error {
  display: none;
  color: var(--color-error);
  font-size: 0.82rem;
  padding: var(--space-3) var(--space-4);
  background: var(--color-error-08);
  border: 1px solid var(--color-error-20);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-4);
}

.form-error.show { display: block; }

/* Form success */
.form-success-msg {
  display: none;
  text-align: center;
  padding: var(--space-10);
}

.form-success-msg.show { display: block; }

.form-success-msg .icon { font-size: 3rem; margin-bottom: var(--space-4); }

.form-success-msg h3 {
  color: var(--color-accent);
  margin-bottom: var(--space-2);
}

.form-success-msg p { color: var(--text-muted); margin-inline: auto; }

/* ============================================================
   SOCIAL LINKS
============================================================ */
.social-links {
  display: flex;
  justify-content: center;
  gap: var(--space-6);
  margin-top: var(--space-8);
  flex-wrap: wrap;
}

.social-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-primary);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--color-primary-20);
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition), border-color var(--transition);
}

.social-link:hover {
  color: var(--color-primary-hover);
  background: var(--color-primary-10);
  border-color: var(--color-primary-50);
}

.social-link__icon { font-size: 1.2rem; }

/* ============================================================
   FOOTER
============================================================ */
footer {
  background: var(--bg-footer);
  text-align: center;
  padding: var(--space-8);
  color: var(--text-muted);
  font-size: 0.88rem;
}

footer a {
  color: var(--color-primary);
  text-decoration: none;
}

footer a:hover { text-decoration: underline; }

/* ============================================================
   BACK TO TOP
============================================================ */
.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 44px;
  height: 44px;
  background: var(--bg-surface-heavy);
  border: 1px solid var(--color-primary-30);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  font-size: 1.1rem;
  cursor: pointer;
  text-decoration: none;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--transition), visibility var(--transition),
              transform var(--transition), box-shadow var(--transition);
  z-index: 998;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  box-shadow: 0 0 20px var(--color-primary-30);
  background: var(--color-primary-10);
}

/* ============================================================
   SECTION VARIANTS
============================================================ */
.section-alt {
  background: var(--gradient-collab-bg);
  border-radius: var(--radius-xl);
  margin: var(--space-8) auto;
}

.section-aiml {
  background: var(--gradient-aiml-bg);
  border-radius: var(--radius-xl);
  margin: var(--space-8) auto;
}

/* ============================================================
   TIMELINE → ACHIEVEMENTS UNIFIED BLOCK
   Merges #building and #achievements into one visual card
   so the timeline flows naturally into the achievement grid.
============================================================ */
#building {
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  margin-bottom: 0;
  border-bottom: none;
}

.section-bridge {
  max-width: 1200px;
  margin: 0 auto;
  background: var(--gradient-collab-bg);
  display: flex;
  align-items: center;
  gap: var(--space-5);
  padding: var(--space-3) var(--space-8);
}

.section-bridge__line {
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--color-primary-30), transparent);
}

.section-bridge__label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-muted);
  white-space: nowrap;
}

#achievements {
  border-radius: 0 0 var(--radius-xl) var(--radius-xl);
  margin-top: 0;
  padding-top: var(--space-10);
}

#achievements .skills-grid {
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
  margin-top: var(--space-6);
}

/* Highlight boxes */
.highlight-box {
  padding: var(--space-6);
  border-radius: var(--radius-md);
  margin: var(--space-6) 0;
}

.highlight-box--warning {
  background: var(--color-warning-10);
  border-left: 3px solid var(--color-warning);
}

.highlight-box--danger {
  background: var(--color-danger-10);
  border-left: 3px solid var(--color-danger);
}

.highlight-box--primary {
  background: var(--color-primary-10);
  border-left: 4px solid var(--color-primary);
}

.highlight-box--secondary {
  background: var(--color-secondary-10);
  border: 1px solid var(--color-secondary-10);
  border-radius: var(--radius-md);
}

.highlight-box--pink {
  background: var(--color-pink-10);
  border: 1px solid var(--color-pink-30);
}

/* Ideation badge */
.ideation-badge {
  position: absolute;
  top: -15px;
  right: 20px;
  background: var(--gradient-aiml);
  padding: 0.4rem 1.2rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--text-on-dark);
  box-shadow: var(--shadow-aiml);
}

/* Team list */
.team-list {
  list-style: disc;
  padding-left: var(--space-6);
  color: var(--text-secondary);
  line-height: 1.9;
}

/* Collaborate grid */
.collab-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-8);
  margin: var(--space-12) 0;
}

.collab-card {
  background: var(--bg-surface);
  padding: var(--space-8);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-primary-20);
  text-align: center;
}

.collab-card .icon { font-size: 3rem; margin-bottom: var(--space-4); display: block; }
.collab-card p { color: var(--text-muted); font-size: 0.88rem; max-width: none; }

/* ============================================================
   RESPONSIVE — TABLET LANDSCAPE  (≤ 1024px)
============================================================ */
@media (max-width: 1024px) {
  section.section        { padding: 4.5rem var(--space-8); }
  .hero                  { padding: 7rem var(--space-8); }
  .projects-grid         { grid-template-columns: repeat(2, 1fr); }
  .lang-grid             { grid-template-columns: repeat(2, 1fr); }
  .cert-grid             { grid-template-columns: repeat(2, 1fr); }
  .skills-grid           { grid-template-columns: repeat(3, 1fr); }
  .collab-grid           { grid-template-columns: repeat(2, 1fr); }
}

/* ============================================================
   RESPONSIVE — TABLET PORTRAIT  (≤ 768px)
============================================================ */
@media (max-width: 768px) {
  /* Nav */
  .nav-links                  { display: none; }
  .mobile-toggle              { display: flex; }
  .mode-toggle-btn__label     { display: none; }

  /* Hero */
  .hero {
    padding: 5.5rem var(--space-6);
    border-radius: var(--radius-lg);
    margin: var(--space-4) auto;
  }

  /* Sections */
  section.section     { padding: 3.5rem var(--space-6); }
  .section-alt        { margin: var(--space-4) auto; }

  /* Revert unified block — show as separate sections on mobile */
  #building           { border-radius: var(--radius-xl); margin-bottom: var(--space-4); border-bottom: 1px solid rgba(96, 165, 250, 0.07); }
  #achievements       { border-radius: var(--radius-xl); margin-top: var(--space-4); padding-top: 3.5rem; }
  #achievements .skills-grid { grid-template-columns: repeat(2, 1fr); }
  .section-bridge     { display: none; }

  /* About */
  .about-content   { flex-direction: column; text-align: center; }
  .about-text p    { margin-inline: auto; }
  .about-image     { flex: 0 0 auto; }
  .profile-avatar  { width: 160px; height: 160px; font-size: 2.5rem; }

  /* Grids */
  .projects-grid   { grid-template-columns: 1fr; }
  .project-card    { min-height: unset; }
  .form-row        { grid-template-columns: 1fr; }
  .skills-grid     { grid-template-columns: repeat(2, 1fr); }
  .lang-grid       { grid-template-columns: repeat(2, 1fr); }
  .cert-grid       { grid-template-columns: repeat(2, 1fr); }
  .collab-grid     { grid-template-columns: repeat(2, 1fr); }

  /* Education subjects */
  .highlight-box ul[style*="grid-template-columns: 1fr 1fr"] {
    grid-template-columns: 1fr !important;
  }

  /* Timeline */
  .build-timeline  { padding-left: 2rem; }

  /* Modal */
  .lang-modal      { max-height: 92vh; }
  .lang-modal-header { padding: var(--space-4) var(--space-6); }
  .lang-modal-body { padding: var(--space-6); }
}

/* ============================================================
   RESPONSIVE — PHONE  (≤ 540px)
============================================================ */
@media (max-width: 540px) {
  /* Hero */
  .hero {
    padding: 4.5rem var(--space-4);
    border-radius: var(--radius-md);
  }
  .hero p { font-size: 1rem; }

  /* Sections */
  section.section { padding: 3rem var(--space-4); }
  .section-alt    { padding: 3rem var(--space-4); }

  /* Nav */
  .logo           { font-size: 1.2rem; }

  /* About */
  .profile-avatar { width: 130px; height: 130px; font-size: 2rem; }

  /* Skills */
  .skills-grid    { grid-template-columns: repeat(2, 1fr); gap: var(--space-4); }
  .skill-card     { padding: var(--space-5); }

  /* Lang cards */
  .lang-grid      { grid-template-columns: repeat(2, 1fr); gap: var(--space-4); }
  .lang-card      { padding: var(--space-5) var(--space-4); }
  .lang-icon      { font-size: 2rem; }

  /* Cert */
  .cert-grid      { grid-template-columns: 1fr; }

  /* Collab */
  .collab-grid    { grid-template-columns: repeat(2, 1fr); }

  /* Build timeline */
  .build-timeline { padding-left: 1.8rem; }
  .build-content  { padding: var(--space-4); }
  .build-header   { gap: var(--space-2); }

  /* Project cards */
  .project-content { padding: var(--space-4); }
  .project-img     { height: 120px; font-size: 0.88rem; letter-spacing: 0.01em; }

  /* Collab cards */
  .collab-card    { padding: var(--space-5); }
  .collab-card .icon { font-size: 2.2rem; }

  /* Highlight boxes — more readable */
  .highlight-box  { padding: var(--space-4); }

  /* Buttons — 44px min touch target */
  .btn            { padding: 0.75rem 1.3rem; font-size: 0.88rem; min-height: 44px; }

  /* Team list tighter */
  .team-list      { line-height: 1.7; }

  /* Modal */
  .lang-modal-header { padding: var(--space-4); }
  .lang-modal-body   { padding: var(--space-4); }
  #langModalGrid     { grid-template-columns: 1fr !important; }
}

/* ============================================================
   RESPONSIVE — SMALL PHONE  (≤ 380px)
============================================================ */
@media (max-width: 380px) {
  .logo             { font-size: 1rem; }
  .mode-toggle-btn  { padding: var(--space-1) var(--space-3); font-size: 0.78rem; }
  section.section   { padding: 2.5rem var(--space-3); }
  .hero             { padding: 3.5rem var(--space-3); }
  .lang-grid        { gap: var(--space-3); }
  .lang-card        { padding: var(--space-4) var(--space-3); }
  .lang-icon        { font-size: 1.7rem; }
  .lang-card h3     { font-size: 0.9rem; }
  .skills-grid      { gap: var(--space-3); }
  .skill-card       { padding: var(--space-4); }
  .skill-icon       { font-size: 2rem; }
  .projects-grid    { gap: var(--space-5); }
  .collab-grid      { gap: var(--space-5); }
  .build-timeline   { padding-left: 1.5rem; }
}

/* ============================================================
   PORTFOLIO MODE TOGGLE
============================================================ */

/* Toggle button in nav */
.mode-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border: 2px solid var(--color-accent);
  border-radius: var(--radius-full);
  background: transparent;
  color: var(--color-accent);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), box-shadow var(--transition);
  white-space: nowrap;
  flex-shrink: 0;
}

.mode-toggle-btn:hover,
.mode-toggle-btn:focus-visible {
  background: var(--color-accent);
  color: var(--bg-base);
  box-shadow: var(--shadow-accent);
  outline: none;
}

body.college-mode .mode-toggle-btn {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

body.college-mode .mode-toggle-btn:hover,
body.college-mode .mode-toggle-btn:focus-visible {
  background: var(--color-primary);
  color: var(--bg-base);
  box-shadow: var(--shadow-primary);
}

/* View visibility — show/hide sections per mode */
body:not(.college-mode) [data-view="college"] { display: none !important; }
body.college-mode [data-view="gamedev"]        { display: none !important; }

/* College hero — accent-tinted gradient to differentiate from gamedev hero */
.college-hero {
  background:
    var(--gradient-hero-radial),
    linear-gradient(45deg, var(--color-accent-30), rgba(16, 185, 129, 0.04));
}

.college-hero .btn-accent {
  box-shadow: var(--shadow-accent);
}
.college-hero .btn-accent:hover {
  box-shadow: var(--shadow-accent-lg);
}

/* ============================================================
   CERTIFICATES
============================================================ */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-6);
}

.cert-card {
  background: var(--bg-surface);
  border: 1px solid var(--color-warning-10);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-4);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.cert-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-warning);
  box-shadow: 0 8px 25px rgba(245, 158, 11, 0.18);
}

.cert-badge {
  font-size: 2.2rem;
  width: 3.8rem;
  height: 3.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-warning-10);
  border-radius: var(--radius-full);
  border: 2px solid rgba(245, 158, 11, 0.25);
}

.cert-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
}

.cert-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-bright);
  line-height: 1.4;
}

.cert-issuer {
  font-size: 0.875rem;
  color: var(--color-warning);
  font-weight: 600;
  max-width: none;
  line-height: 1.4;
}

.cert-date {
  font-size: 0.8rem;
  color: var(--text-muted);
  max-width: none;
}

.cert-btn {
  margin-top: var(--space-2);
  font-size: 0.82rem;
  padding: 0.45rem 1rem;
}

.cert-note {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-top: var(--space-8);
  font-style: italic;
  max-width: none;
}

/* ============================================================
   BUILD TIMELINE
============================================================ */
.build-timeline {
  max-width: 780px;
  margin: 0 auto;
  position: relative;
  padding-left: 2.5rem;
}

.build-timeline::before {
  content: '';
  position: absolute;
  left: 0.85rem;
  top: 0.4rem;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-primary-30), transparent);
}

.build-item {
  position: relative;
  margin-bottom: var(--space-8);
}

.build-item:last-child { margin-bottom: 0; }

.build-marker {
  position: absolute;
  left: -1.65rem;
  top: 0.95rem;
  width: 0.75rem;
  height: 0.75rem;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  border: 2px solid var(--bg-base);
  box-shadow: 0 0 0 3px var(--color-primary-20);
}

.build-marker--completed {
  background: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-30);
}

.build-marker--planned {
  background: var(--text-muted);
  box-shadow: 0 0 0 3px rgba(156, 163, 175, 0.2);
}

.build-content {
  background: var(--bg-surface);
  border: 1px solid var(--color-primary-10);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.build-content:hover {
  border-color: var(--color-primary-30);
  box-shadow: var(--shadow-primary);
}

.build-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-bottom: var(--space-2);
}

.build-status {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.22rem 0.7rem;
  border-radius: var(--radius-full);
  white-space: nowrap;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.build-status--progress {
  background: var(--color-primary-10);
  color: var(--color-primary);
  border: 1px solid var(--color-primary-20);
}

.build-status--completed {
  background: var(--color-accent-30);
  color: var(--color-accent);
  border: 1px solid var(--color-accent-30);
}

.build-status--planned {
  background: rgba(156, 163, 175, 0.10);
  color: var(--text-muted);
  border: 1px solid rgba(156, 163, 175, 0.2);
}

.build-period {
  font-size: 0.82rem;
  color: var(--color-warning);
  font-weight: 600;
  margin-bottom: var(--space-3);
  max-width: none;
}

.build-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
  max-width: none;
}

.build-progress-track {
  background: rgba(255, 255, 255, 0.07);
  border-radius: var(--radius-full);
  height: 6px;
  overflow: hidden;
  margin-bottom: var(--space-2);
}

.build-progress-fill {
  height: 100%;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary-dark));
}

.build-progress-fill--completed {
  background: var(--gradient-accent);
}

.build-progress-fill--planned {
  background: linear-gradient(90deg, var(--text-muted), rgba(156, 163, 175, 0.5));
}

.build-progress-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  max-width: none;
  margin-bottom: 0;
}

.build-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.build-tag {
  font-size: 0.72rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  background: var(--color-secondary-10);
  color: var(--color-secondary-dark);
  font-weight: 600;
  letter-spacing: 0.02em;
}

/* ============================================================
   LANGUAGE SKILL CARDS
============================================================ */
.lang-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  margin-bottom: var(--space-12);
}

.lang-card {
  background: var(--bg-surface);
  border: 2px solid var(--color-primary-10);
  border-radius: var(--radius-lg);
  padding: var(--space-8) var(--space-6);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  cursor: pointer;
  text-align: center;
  transition: transform var(--transition), border-color var(--transition),
              box-shadow var(--transition), background var(--transition);
}

.lang-card:hover {
  transform: translateY(-5px);
  border-color: var(--color-primary-40);
  box-shadow: var(--shadow-primary-lg);
  background: var(--color-primary-10);
}

.lang-card.active {
  border-color: var(--color-primary);
  background: var(--color-primary-10);
  box-shadow: var(--shadow-primary-lg);
}

.lang-icon {
  font-size: 2.5rem;
  line-height: 1;
}

.lang-card h3 {
  font-size: 1.15rem;
  color: var(--text-bright);
}

.lang-cta {
  font-size: 0.78rem;
  color: var(--color-primary);
  font-weight: 700;
  letter-spacing: 0.03em;
  opacity: 0;
  transform: translateY(4px);
  transition: opacity var(--transition), transform var(--transition);
}

.lang-card:hover .lang-cta,
.lang-card.active .lang-cta {
  opacity: 1;
  transform: translateY(0);
}

/* Concept chips */
.concept-section {
  text-align: center;
}

.concept-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: var(--space-4);
  max-width: none;
}

.concept-chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
}

.concept-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.5rem 1.2rem;
  background: var(--color-secondary-10);
  border: 1px solid var(--color-secondary-10);
  border-radius: var(--radius-full);
  color: var(--color-secondary);
  font-weight: 700;
  font-size: 0.9rem;
}

/* Language badge on project card */
.proj-lang-badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.18rem 0.65rem;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-3);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.proj-lang-badge--python { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.proj-lang-badge--c      { background: rgba(107, 114, 128, 0.15); color: #9ca3af; }
.proj-lang-badge--cpp    { background: var(--color-secondary-10); color: var(--color-secondary); }
.proj-lang-badge--java   { background: rgba(249, 115, 22, 0.15); color: var(--color-orange); }

/* ============================================================
   LANGUAGE PROJECTS MODAL
============================================================ */
.lang-modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 0;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.lang-modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.lang-modal {
  background: var(--bg-deep);
  border: 1px solid var(--color-primary-20);
  border-bottom: none;
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  width: 100%;
  max-width: 1100px;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  transform: translateY(100%);
  transition: transform 0.35s cubic-bezier(0.32, 0.72, 0, 1);
  box-shadow: 0 -8px 40px rgba(0, 0, 0, 0.5);
}

.lang-modal-overlay.open .lang-modal {
  transform: translateY(0);
}

.lang-modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-6) var(--space-8);
  border-bottom: 1px solid var(--color-primary-10);
  flex-shrink: 0;
}

.lang-modal-title-group {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.lang-modal-icon {
  font-size: 2rem;
  line-height: 1;
}

.lang-modal-title {
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  color: var(--text-bright);
  margin: 0;
}

.lang-modal-close {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-primary-20);
  background: transparent;
  color: var(--text-muted);
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  flex-shrink: 0;
}

.lang-modal-close:hover {
  background: var(--color-error-08);
  border-color: var(--color-error-20);
  color: var(--color-error);
}

.lang-modal-body {
  overflow-y: auto;
  padding: var(--space-8);
  flex: 1;
  /* Custom scrollbar */
  scrollbar-width: thin;
  scrollbar-color: var(--color-primary-30) transparent;
}

.lang-modal-body::-webkit-scrollbar       { width: 5px; }
.lang-modal-body::-webkit-scrollbar-track { background: transparent; }
.lang-modal-body::-webkit-scrollbar-thumb { background: var(--color-primary-30); border-radius: 99px; }

.lang-modal-empty {
  display: none;
  text-align: center;
  color: var(--text-muted);
  font-style: italic;
  padding: var(--space-12) 0;
  max-width: none;
}

/* Certificate org badge variants */
.cert-badge--internshala { background: rgba(22, 163, 74, 0.12); border-color: rgba(22, 163, 74, 0.25); }
.cert-badge--coursera    { background: rgba(37, 99, 235, 0.12); border-color: rgba(37, 99, 235, 0.25); }
.cert-badge--ixdf        { background: var(--color-secondary-10); border-color: rgba(168, 85, 247, 0.25); }

@media (max-width: 768px) {
  .cert-grid        { grid-template-columns: 1fr 1fr; }
  .build-timeline   { padding-left: 2rem; }
  .lang-grid        { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .cert-grid        { grid-template-columns: 1fr; }
  .lang-grid        { grid-template-columns: 1fr 1fr; }
}