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

:root {
  --bg: #0f1117;
  --surface: #181a20;
  --border: #2a2d37;
  --border-hover: #4f46e5;
  --text: #e4e4e7;
  --text-muted: #9ca3af;
  --accent: #4f46e5;
  --accent-light: #6366f1;
  --tag-js-bg: #4f46e5;
  --tag-form-bg: #10b981;
  --tag-html-bg: #f59e0b;
  --tag-clock-bg: #ef4444;
  --tag-todo-bg: #8b5cf6;
  --tag-btn-bg: #ec4899;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  height: 64px;
  background: rgba(15, 17, 23, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 0.5rem;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1.15rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  border: 1px solid transparent;
  transition: all var(--transition);
  cursor: pointer;
}

.nav-btn:hover {
  color: var(--text);
  background: rgba(79, 70, 229, 0.1);
  border-color: var(--border-hover);
}

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

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all var(--transition);
}

.mobile-menu {
  display: none;
  flex-direction: column;
  gap: 0.5rem;
  padding: 1rem 2rem 1.5rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

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

@media (max-width: 700px) {
  .nav-links {
    display: none;
  }
  .nav-toggle {
    display: flex;
  }
}

/* ===== Main Content ===== */
.content {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

.page-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 2rem;
  letter-spacing: -0.5px;
}

/* ===== Card Grid ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 1.25rem;
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  min-height: 180px;
}

.card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  padding: 1px;
  background: linear-gradient(135deg, var(--accent-light), transparent 60%);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity var(--transition);
}

.card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(79, 70, 229, 0.12);
}

.card:hover::before {
  opacity: 1;
}

.card-tags {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.tag {
  display: inline-block;
  padding: 0.2rem 0.65rem;
  border-radius: 4px;
  font-size: 0.72rem;
  font-weight: 600;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.tag-js { background: var(--tag-js-bg); }
.tag-form { background: var(--tag-form-bg); }
.tag-html { background: var(--tag-html-bg); }
.tag-clock { background: var(--tag-clock-bg); }
.tag-todo { background: var(--tag-todo-bg); }
.tag-btn { background: var(--tag-btn-bg); }

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--text);
}

.card-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: auto;
}

.card-date {
  display: block;
  margin-top: 1rem;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
}

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

.modal {
  width: 90%;
  max-width: 720px;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transform: translateY(20px) scale(0.97);
  transition: transform var(--transition);
  overflow: hidden;
}

.modal-overlay.open .modal {
  transform: translateY(0) scale(1);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.modal-title {
  font-size: 1.15rem;
  font-weight: 600;
}

.modal-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text);
  font-size: 1.3rem;
  cursor: pointer;
  transition: all var(--transition);
}

.modal-close:hover {
  background: rgba(239, 68, 68, 0.15);
  border-color: #ef4444;
  color: #ef4444;
}

.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  flex: 1;
}

.code-block {
  background: #0d0f14;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  overflow-x: auto;
  font-family: 'Courier New', Consolas, monospace;
  font-size: 0.82rem;
  line-height: 1.7;
  color: #c9d1d9;
  white-space: pre;
  tab-size: 2;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border);
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.25rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.copy-btn:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
}

.copy-btn.copied {
  background: #10b981;
}

/* ===== Auth Modal ===== */
.auth-modal {
  position: relative;
  width: 90%;
  max-width: 420px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  transform: translateY(20px) scale(0.97);
  transition: transform var(--transition);
}

.modal-overlay.open .auth-modal {
  transform: translateY(0) scale(1);
}

.auth-modal .modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

.auth-form.hidden {
  display: none;
}

.auth-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.auth-subtitle {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
}

.auth-input-group {
  margin-bottom: 1.15rem;
}

.auth-input-group label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.auth-input-group input {
  width: 100%;
  padding: 0.7rem 0.9rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.9rem;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition);
}

.auth-input-group input:focus {
  border-color: var(--accent);
}

.auth-input-group input::placeholder {
  color: #555;
}

.auth-submit-btn {
  width: 100%;
  padding: 0.75rem;
  margin-top: 0.5rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition);
}

.auth-submit-btn:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
}

.auth-toggle {
  text-align: center;
  margin-top: 1.25rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.auth-toggle a {
  color: var(--accent-light);
  text-decoration: none;
  font-weight: 600;
  cursor: pointer;
}

.auth-toggle a:hover {
  text-decoration: underline;
}

/* ===== Search Bar ===== */
.search-bar {
  position: relative;
  margin-bottom: 2rem;
  max-width: 480px;
}

.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.search-bar input {
  width: 100%;
  padding: 0.75rem 1rem 0.75rem 2.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.9rem;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition);
}

.search-bar input:focus {
  border-color: var(--accent);
}

.search-bar input::placeholder {
  color: #555;
}

.card.hidden-by-search {
  display: none;
}

.no-results {
  grid-column: 1 / -1;
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ===== Responsive ===== */
@media (max-width: 500px) {
  .navbar {
    padding: 0 1rem;
  }
  .content {
    padding: 1.5rem 1rem 3rem;
  }
  .card-grid {
    grid-template-columns: 1fr;
  }
  .modal {
    width: 95%;
  }
}