/* ==========================================================================
   Sagnik — Warm Minimal Portfolio
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Newsreader:ital,opsz,wght@0,6..72,300;0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400;1,6..72,500&family=Karla:ital,wght@0,300;0,400;0,500;0,600;0,700;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* ==========================================================================
   Custom Properties
   ========================================================================== */

:root {
  --bg:             #FAFAF7;
  --bg-elevated:    #FFFFFF;
  --bg-subtle:      #F3F2EE;
  --border:         #E5E3DD;
  --border-hover:   #D0CEC7;
  --text:           #1C1C1C;
  --text-secondary: #555550;
  --text-dim:       #8A8A82;
  --accent:         #B34A28;
  --accent-hover:   #9A3D1F;
  --accent-light:   rgba(179, 74, 40, 0.08);
  --code-bg:        #F5F4F0;
  --code-border:    #E5E3DD;
  --shadow-sm:      0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:      0 4px 16px rgba(0,0,0,0.06);
  --shadow-lg:      0 8px 30px rgba(0,0,0,0.08);
  --serif:          'Newsreader', Georgia, 'Times New Roman', serif;
  --sans:           'Karla', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono:           'JetBrains Mono', 'Fira Code', monospace;
  --max-width:      720px;
  --max-width-wide: 960px;
  --nav-height:     60px;
  --ease-out:       cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring:    cubic-bezier(0.34, 1.56, 0.64, 1);
}

[data-theme="dark"] {
  --bg:             #141416;
  --bg-elevated:    #1C1C1F;
  --bg-subtle:      #1F1F22;
  --border:         #2A2A2E;
  --border-hover:   #3A3A3F;
  --text:           #E3E1DC;
  --text-secondary: #9A988F;
  --text-dim:       #5F5F58;
  --accent:         #D4663F;
  --accent-hover:   #E07A55;
  --accent-light:   rgba(212, 102, 63, 0.1);
  --code-bg:        #1A1A1D;
  --code-border:    #2A2A2E;
  --shadow-sm:      0 1px 2px rgba(0,0,0,0.15);
  --shadow-md:      0 4px 16px rgba(0,0,0,0.25);
  --shadow-lg:      0 8px 30px rgba(0,0,0,0.35);
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--bg);
  transition: background-color 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

::selection {
  background: var(--accent);
  color: #fff;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

/* ==========================================================================
   Typography
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--serif);
  font-weight: 500;
  line-height: 1.25;
  color: var(--text);
  letter-spacing: -0.01em;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.375rem; }
h4 { font-size: 1.125rem; }

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Layout
   ========================================================================== */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.container--wide {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================================================
   Navigation
   ========================================================================== */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background-color 0.3s ease;
}

.nav__inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-family: var(--serif);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

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

.nav__links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav__link {
  font-family: var(--sans);
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s ease;
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--accent);
  transition: width 0.3s var(--ease-out);
}

.nav__link:hover::after,
.nav__link--active::after {
  width: 100%;
}

.nav__link:hover,
.nav__link--active {
  color: var(--text);
}

.nav__theme-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-dim);
  cursor: pointer;
  transition: all 0.2s ease;
}

.nav__theme-btn:hover {
  border-color: var(--border-hover);
  color: var(--text);
  transform: rotate(15deg);
}

/* Mobile nav */
.nav__mobile-btn {
  display: none;
  width: 32px;
  height: 32px;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
}

@media (max-width: 768px) {
  .nav__links { display: none; }
  .nav__mobile-btn { display: flex; }
}

.nav__mobile-menu {
  display: none;
  border-top: 1px solid var(--border);
  padding: 12px 24px 16px;
  background: color-mix(in srgb, var(--bg) 95%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav__mobile-menu.is-open {
  display: block;
  animation: slideDown 0.25s var(--ease-out);
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

.nav__mobile-menu a {
  display: block;
  padding: 8px 0;
  font-size: 0.95rem;
  color: var(--text-dim);
}

.nav__mobile-menu a:hover,
.nav__mobile-menu a.nav__link--active {
  color: var(--text);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
  border-top: 1px solid var(--border);
  margin-top: 80px;
  padding: 32px 0;
}

.footer__inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer__links {
  display: flex;
  align-items: center;
  gap: 20px;
}

.footer__link {
  font-size: 0.85rem;
  color: var(--text-dim);
  transition: color 0.2s ease;
}

.footer__link:hover {
  color: var(--text);
}

.footer__copy {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ==========================================================================
   Reading Progress Bar
   ========================================================================== */

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  background: var(--accent);
  z-index: 10000;
  width: 0%;
  transition: width 0.1s linear;
}

/* ==========================================================================
   Tags
   ========================================================================== */

.tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  font-family: var(--sans);
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--text-dim);
  background: var(--bg-subtle);
  border-radius: 4px;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.tag:hover {
  color: var(--accent);
  background: var(--accent-light);
}

/* ==========================================================================
   Cards
   ========================================================================== */

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
  transition: transform 0.3s var(--ease-out), border-color 0.2s ease, box-shadow 0.3s var(--ease-out);
}

.card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* Project card specific */
.project-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
  transition: transform 0.3s var(--ease-out), border-color 0.25s ease, box-shadow 0.3s var(--ease-out);
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent);
  transition: height 0.3s var(--ease-out);
  border-radius: 0 0 3px 0;
}

.project-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.project-card:hover::before {
  height: 100%;
}

.project-card__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 8px;
}

.project-card__title {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text);
}

.project-card__links {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
  margin-top: 2px;
}

.project-card__link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  color: var(--text-dim);
  background: var(--bg-subtle);
  transition: all 0.2s ease;
}

.project-card__link:hover {
  color: var(--accent);
  background: var(--accent-light);
}

.project-card__desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.project-card__tech {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  font-family: var(--sans);
  font-size: 0.9rem;
  font-weight: 500;
  border: 1px solid transparent;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.btn--primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.btn--primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn--outline {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}

.btn--outline:hover {
  border-color: var(--text-dim);
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--text-dim);
  border-color: transparent;
  padding: 6px 12px;
  font-size: 0.85rem;
}

.btn--ghost:hover {
  color: var(--accent);
  background: var(--accent-light);
}

/* ==========================================================================
   Blog Post Prose
   ========================================================================== */

.prose-content {
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

.prose-content h2 {
  margin-top: 48px;
  margin-bottom: 16px;
  font-size: 1.625rem;
  color: var(--text);
}

.prose-content h3 {
  margin-top: 36px;
  margin-bottom: 12px;
  font-size: 1.25rem;
  color: var(--text);
}

.prose-content p {
  margin-bottom: 1.25rem;
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.8;
}

.prose-content ul,
.prose-content ol {
  margin-bottom: 1.25rem;
  padding-left: 24px;
  color: var(--text-secondary);
}

.prose-content ul { list-style: disc; }
.prose-content ol { list-style: decimal; }

.prose-content li {
  margin-bottom: 6px;
  line-height: 1.75;
  font-family: var(--serif);
  font-size: 1.1rem;
}

.prose-content blockquote {
  border-left: 3px solid var(--accent);
  padding: 12px 20px;
  margin: 24px 0;
  background: var(--accent-light);
  border-radius: 0 6px 6px 0;
  color: var(--text-secondary);
  font-style: italic;
}

.prose-content blockquote p {
  margin-bottom: 0;
}

.prose-content a {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--accent-light);
  transition: text-decoration-color 0.2s ease;
}

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

.prose-content img {
  margin: 28px 0;
  border-radius: 8px;
}

.prose-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 40px 0;
}

.prose-content strong {
  color: var(--text);
  font-weight: 600;
}

.prose-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-family: var(--sans);
  font-size: 0.95rem;
}

.prose-content th,
.prose-content td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.prose-content th {
  font-weight: 600;
  color: var(--text);
}

/* ==========================================================================
   Code Blocks
   ========================================================================== */

code {
  font-family: var(--mono);
  font-size: 0.875em;
}

:not(pre) > code {
  padding: 2px 6px;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 4px;
  color: var(--accent);
  font-size: 0.85em;
}

pre {
  position: relative;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 8px;
  padding: 20px;
  margin: 24px 0;
  overflow-x: auto;
  line-height: 1.6;
  font-size: 0.875rem;
}

[data-theme="dark"] pre {
  background: #0D0D0F;
  border-color: #2A2A2E;
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
  border: none;
  border-radius: 0;
}

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 4px 10px;
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-dim);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
  opacity: 0;
}

pre:hover .copy-btn {
  opacity: 1;
}

.copy-btn:hover {
  color: var(--text);
  border-color: var(--border-hover);
}

/* ==========================================================================
   Search
   ========================================================================== */

.search-input {
  width: 100%;
  padding: 12px 16px 12px 44px;
  font-family: var(--sans);
  font-size: 1rem;
  color: var(--text);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-input::placeholder {
  color: var(--text-dim);
}

.search-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}

/* ==========================================================================
   Post List Item
   ========================================================================== */

.post-item {
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
  transition: background-color 0.15s ease;
}

.post-item:last-child {
  border-bottom: none;
}

.post-item__title {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text);
  transition: color 0.2s ease;
}

.post-item__meta {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.post-item__desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ==========================================================================
   Section heading
   ========================================================================== */

.section-label {
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

/* Section header with "View all" link */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 20px;
}

.section-header__title {
  font-family: var(--serif);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text);
}

.section-header__link {
  font-size: 0.85rem;
  color: var(--text-dim);
  transition: color 0.2s ease;
}

.section-header__link:hover {
  color: var(--accent);
}

/* Divider */
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0;
}

/* ==========================================================================
   TOC
   ========================================================================== */

.toc-link {
  transition: color 0.15s ease;
}

.toc-link:hover {
  color: var(--accent) !important;
}

/* ==========================================================================
   Contact card
   ========================================================================== */

.contact-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  transition: transform 0.3s var(--ease-out), border-color 0.2s ease, box-shadow 0.3s var(--ease-out);
  text-decoration: none;
}

.contact-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  color: inherit;
}

.contact-card__icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  background: var(--accent-light);
  color: var(--accent);
}

/* ==========================================================================
   Animations
   ========================================================================== */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-up {
  opacity: 0;
  transform: translateY(16px);
}

.animate-up.is-visible {
  animation: fadeUp 0.6s var(--ease-out) forwards;
}

.stagger-1 { animation-delay: 0.08s; }
.stagger-2 { animation-delay: 0.16s; }
.stagger-3 { animation-delay: 0.24s; }
.stagger-4 { animation-delay: 0.32s; }
.stagger-5 { animation-delay: 0.40s; }

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  body { font-size: 15px; }

  .prose-content {
    font-size: 1rem;
  }

  .prose-content p,
  .prose-content li {
    font-size: 1rem;
  }

  .footer__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }
}

@media (max-width: 480px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.35rem; }
}

/* ==========================================================================
   Print
   ========================================================================== */

@media print {
  body { background: #fff; color: #000; }
  .nav, .reading-progress, .copy-btn, .footer { display: none !important; }
  a { color: #000; text-decoration: underline; }
  .card, .project-card, .contact-card { border: 1px solid #ccc; box-shadow: none; break-inside: avoid; }
  pre { border: 1px solid #ccc; white-space: pre-wrap; }
}