:root {
  --color-bg: #FDF6EE;
  --color-surface: #FFFFFF;
  --color-primary: #C77D4A;
  --color-primary-light: #F5E6D8;
  --color-primary-dark: #A8663A;
  --color-secondary: #9B6B43;
  --color-text: #3D2B1F;
  --color-text-secondary: #8B7355;
  --color-border: #EDE0D4;
  --color-gold: #D4A373;
  --color-success: #2E7D64;
  --color-warning: #D95C3B;
  --color-danger: #C0392B;

  --shadow-sm: 0 1px 3px rgba(61, 43, 31, 0.08);
  --shadow-md: 0 4px 12px rgba(61, 43, 31, 0.1);
  --shadow-lg: 0 8px 30px rgba(61, 43, 31, 0.12);

  --radius: 16px;
  --radius-sm: 10px;

  --font-display: 'Instrument Serif', serif;
  --font-body: 'Source Sans 3', sans-serif;

  --header-height: 56px;
  --tab-height: 64px;
  --sidebar-width: 240px;
  --max-content: 480px;
}

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

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

ul, ol {
  list-style: none;
}

input, textarea, select, button {
  font-family: inherit;
  font-size: inherit;
}

/* ===== Page Container ===== */
.page {
  flex: 1;
  padding: 0 16px 80px;
  max-width: var(--max-content);
  margin: 0 auto;
  width: 100%;
  animation: fadeInUp 0.35s ease;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Card ===== */
.card {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card + .card {
  margin-top: 12px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  transition: all 0.2s;
  border: 2px solid transparent;
  font-family: var(--font-body);
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.97);
}

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

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

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

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

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

.btn-danger:hover {
  opacity: 0.9;
}

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

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

.btn-block {
  display: flex;
  width: 100%;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
}

.btn-xs {
  padding: 3px 10px;
  font-size: 12px;
}

.btn-lg {
  padding: 14px 28px;
  font-size: 17px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* ===== Form Styles ===== */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 12px 14px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--color-text);
  background: var(--color-surface);
  transition: border-color 0.2s;
  outline: none;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--color-primary);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-secondary);
  opacity: 0.6;
}

.form-textarea {
  min-height: 100px;
  resize: vertical;
  line-height: 1.5;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%238B7355' d='M6 8L0 0h12z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
  cursor: pointer;
}

.form-hint {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-top: 4px;
}

.form-error {
  font-size: 13px;
  color: var(--color-danger);
  margin-top: 4px;
}

/* ===== Toast Messages ===== */
.toast {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  color: #fff;
  z-index: 300;
  opacity: 0;
  max-width: 90vw;
  text-align: center;
  box-shadow: var(--shadow-lg);
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toast-success {
  background: var(--color-success);
}

.toast-error {
  background: var(--color-danger);
}

.toast-info {
  background: var(--color-primary);
}

/* ===== Empty State ===== */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
  text-align: center;
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.6;
}

.empty-state-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}

.empty-state-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
  max-width: 280px;
}

/* ===== Tags ===== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  line-height: 1;
}

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

.tag-success {
  background: #E8F5E9;
  color: var(--color-success);
}

.tag-warning {
  background: #FFF3E0;
  color: var(--color-warning);
}

.tag-danger {
  background: #FFEBEE;
  color: var(--color-danger);
}

.tag-gray {
  background: #F0ECE6;
  color: var(--color-text-secondary);
}

/* ===== Divider ===== */
.divider {
  height: 1px;
  background: var(--color-border);
  margin: 16px 0;
  border: none;
}

/* ===== Desktop Layout ===== */
@media (min-width: 768px) {
  #app {
    flex-direction: row;
  }

  .sidebar {
    display: flex;
  }

  .main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    min-height: 100vh;
  }

  .mobile-tab-bar {
    display: none;
  }

  .page {
    padding: 24px 32px 40px;
    max-width: 720px;
  }
}

/* ===== Mobile Layout ===== */
@media (max-width: 767px) {
  .sidebar {
    display: none;
  }

  .mobile-tab-bar {
    display: flex;
  }

  .main-content {
    flex: 1;
  }

  .page {
    padding: 0 16px calc(80px + var(--tab-height));
  }
}