/* ==========================================================================
   CSS DESIGN SYSTEM - MINIMALIST EDITORIAL PORTFOLIO
   ========================================================================== */

:root {
  /* Warm Slate & Paper Colors */
  --bg-body: #fbfaf7; /* Warm Paper White */
  --text-primary: #1a1a1a; /* Soft Black */
  --text-secondary: #5e5e5e; /* Warm Grey */
  --text-muted: #8e8e8e;
  --border-base: rgba(26, 26, 26, 0.08);
  --accent: #ff3300; /* Vermillion Accent */
  --accent-rgb: 255, 51, 0;
  
  --selection-bg: rgba(255, 51, 0, 0.1);
  --selection-text: #1a1a1a;

  /* Typography Pairing */
  --font-sans: "Inter", ui-sans-serif, system-ui, sans-serif;
  --font-serif: "Lora", Georgia, serif;
  --font-mono: "Space Mono", ui-monospace, monospace;
  
  /* Transitions */
  --trans: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

html.dark {
  /* Deep Space Charcoal Colors */
  --bg-body: #0b0b0b; /* Deep Soft Black */
  --text-primary: #e5e5e5; /* Warm White */
  --text-secondary: #8e8e8e; /* Warm Grey */
  --text-muted: #5c5c5c;
  --border-base: rgba(229, 229, 229, 0.08);
  --accent: #ff5533; /* Warm Vermillion */
  --accent-rgb: 255, 85, 51;
  
  --selection-bg: rgba(255, 85, 51, 0.2);
  --selection-text: #e5e5e5;
}

/* ==========================================================================
   BASE & RESET
   ========================================================================== */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scrollbar-gutter: stable;
}

body {
  background-color: var(--bg-body);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.625;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--trans), color var(--trans), border-color var(--trans);
}

::selection {
  background-color: var(--selection-bg);
  color: var(--selection-text);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.25;
}

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: rgba(var(--accent-rgb), 0.3);
  text-underline-offset: 4px;
  transition: color var(--trans), text-decoration-color var(--trans);
}

a:hover {
  color: var(--accent);
  text-decoration-color: var(--accent);
}

/* ==========================================================================
   LAYOUT STRUCTURE
   ========================================================================== */

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 80px 32px;
}

/* ==========================================================================
   HEADER
   ========================================================================== */

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.header-logo {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-decoration: none;
  color: var(--text-primary);
}

.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: color var(--trans);
}

.theme-toggle:hover {
  color: var(--accent);
}

/* ==========================================================================
   INTRO SECTION
   ========================================================================== */

.intro-name {
  font-size: clamp(2rem, 6vw, 3rem);
  font-weight: 500;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.intro-tagline {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 24px;
  letter-spacing: 0.02em;
  font-weight: bold;
}

.intro-bio {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
}

.social-link {
  text-decoration: none;
  border-bottom: 1px solid rgba(var(--accent-rgb), 0.3);
  padding-bottom: 2px;
}

.social-link:hover {
  border-bottom-color: var(--accent);
}

/* ==========================================================================
   SECTIONS & ACCORDIONS
   ========================================================================== */

.section-title {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 500;
  margin-top: 56px;
  margin-bottom: 24px;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-base);
  padding-bottom: 6px;
}

/* Item Grouping */
.item-group {
  margin-bottom: 30px;
}

.item-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 4px;
}

.item-title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-primary);
}

.item-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.item-subtitle {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  margin-bottom: 8px;
  text-transform: uppercase;
  font-weight: bold;
}

/* Bullets */
.bullet-list {
  padding-left: 20px;
  list-style-type: square;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.bullet-list li {
  margin-bottom: 6px;
}

.bullet-list li::marker {
  color: var(--accent);
}

/* Tag list */
.tag-container {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 12px;
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-secondary);
  border: 1px solid var(--border-base);
  padding: 1px 6px;
  border-radius: 3px;
  background-color: transparent;
  text-transform: uppercase;
}

/* ==========================================================================
   TECHNICAL NOTES
   ========================================================================== */

.notes-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.note-item {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-bottom: 1px dotted var(--border-base);
  padding-bottom: 10px;
  text-decoration: none;
}

@media (min-width: 36rem) {
  .note-item {
    flex-direction: row;
    align-items: center;
  }
}

.note-title {
  font-size: 0.95rem;
  color: var(--text-primary);
  font-family: var(--font-sans);
  text-decoration: none;
  font-weight: 500;
  border-bottom: 1px solid transparent;
  transition: border-color var(--trans), color var(--trans);
}

.note-item:hover .note-title {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.note-meta {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

/* ==========================================================================
   NOW SECTION
   ========================================================================== */

.now-list {
  padding-left: 20px;
  list-style-type: square;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.now-list li {
  margin-bottom: 8px;
}

.now-list li::marker {
  color: var(--accent);
}

/* ==========================================================================
   SKILLS ROW
   ========================================================================== */

.skills-stack {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.skills-row {
  display: grid;
  grid-template-columns: 1fr;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-base);
  gap: 6px;
}

@media (min-width: 36rem) {
  .skills-row {
    grid-template-columns: 140px 1fr;
    align-items: start;
  }
}

.skills-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--text-muted);
}

.skills-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.skill-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 2px 6px;
  border: 1px solid var(--border-base);
  border-radius: 4px;
  color: var(--text-secondary);
  transition: border-color var(--trans), color var(--trans);
  cursor: default;
}

.skill-tag:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ==========================================================================
   IIT BHU EDUCATION & LOGO
   ========================================================================== */

.edu-layout {
  display: flex;
  align-items: center;
  gap: 16px;
}

.iit-emblem-svg-container {
  width: 46px;
  height: 46px;
  flex-shrink: 0;
  background-color: #ffffff;
  border: 1px solid var(--border-base);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.iit-emblem-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 4px;
}

/* ==========================================================================
   CONTACT
   ========================================================================== */

.contact-box {
  padding: 10px 0;
}

.contact-text {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 18px;
}

/* ==========================================================================
   PROJECT CARDS (Ankit-style grid)
   ========================================================================== */

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 8px;
}

@media (max-width: 34rem) {
  .project-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 22rem) {
  .project-grid {
    grid-template-columns: 1fr;
  }
}

.project-card {
  border: 1px solid var(--border-base);
  border-radius: 12px;
  overflow: hidden;
  background-color: var(--bg-body);
  transition: border-color var(--trans), transform var(--trans);
}

.project-card:hover {
  border-color: rgba(var(--accent-rgb), 0.5);
  transform: translateY(-2px);
}

.project-cover {
  display: block;
  aspect-ratio: 16 / 10;
  text-decoration: none;
  background: #0b0b0b;
  overflow: hidden;
}

.project-cover-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.project-body {
  padding: 12px;
}

.project-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.project-name {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

.project-year {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
}

.project-desc {
  margin-top: 6px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.project-links {
  margin-top: 12px;
  display: flex;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.project-links a {
  text-decoration: none;
  color: var(--accent);
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: border-color var(--trans);
}

.project-links a:hover {
  border-bottom-color: var(--accent);
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

.site-footer {
  margin-top: 80px;
  border-top: 1px solid var(--border-base);
  padding: 20px 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

@media (min-width: 36rem) {
  .site-footer {
    flex-direction: row;
  }
}

/* ==========================================================================
   SECTION TOGGLE BAR
   ========================================================================== */

.tab-bar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 14px 24px;
  margin: 0 -24px 36px;
  background-color: var(--bg-body);
  border-bottom: 1px solid var(--border-base);
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.tab-bar::-webkit-scrollbar {
  display: none;
}

.tab-btn {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  background: none;
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 6px 14px;
  cursor: pointer;
  white-space: nowrap;
  transition: color var(--trans), border-color var(--trans),
    background-color var(--trans);
}

.tab-btn:hover {
  color: var(--accent);
  border-color: rgba(var(--accent-rgb), 0.25);
}

.tab-btn.active {
  color: var(--accent);
  border-color: rgba(var(--accent-rgb), 0.4);
  background-color: rgba(var(--accent-rgb), 0.07);
}

/* Theme toggle sits on the left, directly under the section toggle bar */
.theme-row {
  display: flex;
  justify-content: flex-start;
  margin-bottom: 28px;
}

/* Offset so the sticky bar never covers a section heading on jump */
main section {
  scroll-margin-top: 84px;
}

/* ==========================================================================
   VIEW SWITCHING (Ankit-style: each tab is its own page)
   ========================================================================== */

main > section {
  animation: viewIn 0.35s ease both;
}

main > section.is-hidden {
  display: none;
  animation: none;
}

@keyframes viewIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}