/* ==================== CSS Variables ==================== */
:root {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-card: #1c2128;
  --bg-input: #0d1117;
  --border: #30363d;
  --border-color: #30363d;
  --accent: #58a6ff;
  --accent-color: #58a6ff;
  --accent-purple: #a371f7;
  --accent-green: #3fb950;
  --accent-orange: #f0883e;
  --accent-pink: #f778ba;
  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --text-muted: #6e7681;
  --text-tertiary: #6e7681;
  --card-bg: #1c2128;
}

/* ==================== Base Styles ==================== */
* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'IBM Plex Sans', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
}

body::before {
  content: '';
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background:
    radial-gradient(ellipse at 20% 20%, rgba(88, 166, 255, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(163, 113, 247, 0.08) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* ==================== Header & Navigation ==================== */
.header {
  padding: 0.75rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(13, 17, 23, 0.95);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.1rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent-purple), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  flex-shrink: 0;
}

.logo-icon {
  width: 28px; height: 28px;
  background: linear-gradient(135deg, var(--accent), var(--accent-purple));
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex: 1;
  justify-content: center;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: all 0.2s;
  white-space: nowrap;
}

.nav-link:hover, .nav-link.active {
  color: var(--accent);
  background: rgba(88, 166, 255, 0.1);
}

.nav-link.active {
  color: var(--accent);
}

.nav-link i { width: 16px; height: 16px; }

.menu-toggle {
  padding: 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.menu-toggle:hover { border-color: var(--accent); color: var(--accent); background: rgba(88, 166, 255, 0.1); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.home-btn {
  padding: 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
}

.home-btn:hover { border-color: var(--accent); color: var(--accent); background: rgba(88, 166, 255, 0.1); }

/* ==================== Sidebar Menu ==================== */
.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 998;
}

.sidebar-overlay.show {
  opacity: 1;
  visibility: visible;
}

.sidebar-menu {
  position: fixed;
  top: 0;
  right: 0;
  width: 280px;
  max-width: 85vw;
  height: 100vh;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border);
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 999;
  display: flex;
  flex-direction: column;
}

.sidebar-menu.show {
  transform: translateX(0);
}

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

.sidebar-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.sidebar-close {
  padding: 0.5rem;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.sidebar-close:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 0.75rem;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.875rem 1rem;
  border-radius: 8px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s;
  margin-bottom: 0.25rem;
}

.sidebar-link:hover {
  background: rgba(88, 166, 255, 0.1);
  color: var(--accent);
}

.sidebar-link.active {
  background: rgba(88, 166, 255, 0.15);
  color: var(--accent);
}

.sidebar-link i {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* ==================== Main Content ==================== */
.main {
  max-width: 1600px;
  margin: 0 auto;
  padding: 2rem;
}

.tool-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.tool-title i { color: var(--accent-purple); }

.tool-desc {
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

/* ==================== Cards ==================== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
}

/* ==================== Form Elements ==================== */
.input-group { margin-bottom: 1.25rem; }

.input-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.input-field {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.875rem;
  transition: all 0.2s;
}

.input-field:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.15);
}

textarea.input-field {
  min-height: 120px;
  resize: vertical;
}

.select-field {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%238b949e' stroke-width='2'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

/* ==================== Buttons ==================== */
.btn {
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-family: 'IBM Plex Sans', sans-serif;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-purple));
  color: white;
}

.btn-primary:hover {
  box-shadow: 0 4px 20px rgba(88, 166, 255, 0.3);
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-primary);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-group {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.copy-btn {
  padding: 0.4rem 0.75rem;
  font-size: 0.75rem;
}

/* ==================== Output ==================== */
.output-box {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  margin-top: 1rem;
}

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}

.output-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}

.output-content {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.875rem;
  line-height: 1.6;
  word-break: break-all;
  color: var(--accent-green);
}

/* ==================== Toast ==================== */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  padding: 1rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--accent-green);
  border-radius: 8px;
  color: var(--accent-green);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  transform: translateX(120%);
  transition: transform 0.3s ease;
  z-index: 1001;
}

.toast.show { transform: translateX(0); }

/* ==================== Footer ==================== */
.footer {
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* ==================== Responsive ==================== */
@media (max-width: 1024px) {
  /* 侧边栏在小屏幕上默认隐藏，通过按钮显示 */
}

@media (max-width: 768px) {
  .header { padding: 0.75rem 1rem; }
  .main { padding: 1rem; }
  .btn-group { flex-direction: column; }
}

/* ==================== Homepage Specific ==================== */
.header.hero-header {
  padding: 1.25rem 2rem;
  background: rgba(13, 17, 23, 0.9);
}

.hero {
  text-align: center;
  padding: 4rem 2rem 3rem;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  margin-bottom: 1rem;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--accent), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.125rem;
  color: var(--text-secondary);
}

.main.homepage-main {
  max-width: 1200px;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  text-decoration: none;
  color: inherit;
  transition: all 0.3s ease;
  display: block;
}

.tool-card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 30px rgba(88, 166, 255, 0.15);
  transform: translateY(-4px);
}

.tool-icon {
  width: 48px; height: 48px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.tool-card:nth-child(1) .tool-icon { background: linear-gradient(135deg, rgba(63, 185, 80, 0.2), rgba(63, 185, 80, 0.05)); color: var(--accent-green); }
.tool-card:nth-child(2) .tool-icon { background: linear-gradient(135deg, rgba(88, 166, 255, 0.2), rgba(88, 166, 255, 0.05)); color: var(--accent); }
.tool-card:nth-child(3) .tool-icon { background: linear-gradient(135deg, rgba(240, 136, 62, 0.2), rgba(240, 136, 62, 0.05)); color: var(--accent-orange); }
.tool-card:nth-child(4) .tool-icon { background: linear-gradient(135deg, rgba(240, 136, 62, 0.2), rgba(240, 136, 62, 0.05)); color: var(--accent-orange); }
.tool-card:nth-child(5) .tool-icon { background: linear-gradient(135deg, rgba(163, 113, 247, 0.2), rgba(163, 113, 247, 0.05)); color: var(--accent-purple); }
.tool-card:nth-child(6) .tool-icon { background: linear-gradient(135deg, rgba(247, 120, 186, 0.2), rgba(247, 120, 186, 0.05)); color: var(--accent-pink); }
.tool-card:nth-child(7) .tool-icon { background: linear-gradient(135deg, rgba(88, 166, 255, 0.2), rgba(88, 166, 255, 0.05)); color: var(--accent); }
.tool-card:nth-child(8) .tool-icon { background: linear-gradient(135deg, rgba(63, 185, 80, 0.2), rgba(63, 185, 80, 0.05)); color: var(--accent-green); }
.tool-card:nth-child(9) .tool-icon { background: linear-gradient(135deg, rgba(163, 113, 247, 0.2), rgba(163, 113, 247, 0.05)); color: var(--accent-purple); }
.tool-card:nth-child(10) .tool-icon { background: linear-gradient(135deg, rgba(240, 136, 62, 0.2), rgba(240, 136, 62, 0.05)); color: var(--accent-orange); }
.tool-card:nth-child(11) .tool-icon { background: linear-gradient(135deg, rgba(247, 120, 186, 0.2), rgba(247, 120, 186, 0.05)); color: var(--accent-pink); }
.tool-card:nth-child(12) .tool-icon { background: linear-gradient(135deg, rgba(88, 166, 255, 0.2), rgba(88, 166, 255, 0.05)); color: var(--accent); }
.tool-card:nth-child(13) .tool-icon { background: linear-gradient(135deg, rgba(63, 185, 80, 0.2), rgba(63, 185, 80, 0.05)); color: var(--accent-green); }
.tool-card:nth-child(14) .tool-icon { background: linear-gradient(135deg, rgba(88, 166, 255, 0.2), rgba(88, 166, 255, 0.05)); color: var(--accent); }
.tool-card:nth-child(15) .tool-icon { background: linear-gradient(135deg, rgba(163, 113, 247, 0.2), rgba(163, 113, 247, 0.05)); color: var(--accent-purple); }
.tool-card:nth-child(16) .tool-icon { background: linear-gradient(135deg, rgba(247, 120, 186, 0.2), rgba(247, 120, 186, 0.05)); color: var(--accent-pink); }

.tool-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.tool-card p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.tool-arrow {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  margin-top: 1rem;
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 500;
}

@media (max-width: 1024px) {
  .tools-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .tools-grid { grid-template-columns: 1fr; }
  .tool-card { padding: 1.25rem; }
}