/* ===== CSS Variables & Theme ===== */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f4f4f5;
  --bg-card: #ffffff;
  --text-primary: #1a1a1a;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --border-color: #e5e7eb;
  --accent: #ff8c00;
  --accent-hover: #e67e00;
  --accent-light: rgba(255, 140, 0, 0.1);
  --success: #22c55e;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
  --transition: 0.2s ease;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* Telegram Dark Theme */
body.dark {
  --bg-primary: #1c1c1e;
  --bg-secondary: #2c2c2e;
  --bg-card: #2c2c2e;
  --text-primary: #f5f5f5;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --border-color: #3a3a3c;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.4);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ===== App Container ===== */
.app {
  max-width: 100%;
  padding-bottom: 100px;
}

/* ===== Header ===== */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-primary);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header__title {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.3px;
}

.header__close {
  width: 32px;
  height: 32px;
  border: none;
  background: var(--bg-secondary);
  border-radius: 50%;
  font-size: 16px;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.header__close:hover {
  background: var(--border-color);
  color: var(--text-primary);
}

/* ===== Filter Items ===== */
.filters {
  padding: 8px 0;
}

.filter-item {
  border-bottom: 1px solid var(--border-color);
}

.filter-item__header {
  display: flex;
  align-items: center;
  padding: 16px 20px;
  cursor: pointer;
  user-select: none;
  transition: background var(--transition);
}

.filter-item__header:hover {
  background: var(--bg-secondary);
}

.filter-item__header:active {
  background: var(--border-color);
}

.filter-item__label {
  flex: 1;
  font-size: 16px;
  font-weight: 400;
  color: var(--text-primary);
}

.filter-item__badge {
  margin-right: 12px;
  padding: 2px 8px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  border-radius: 10px;
  min-width: 20px;
  text-align: center;
  display: none;
}

.filter-item__badge.visible {
  display: inline-block;
}

.filter-item__icon {
  font-size: 20px;
  color: var(--text-muted);
  transition: transform var(--transition);
  line-height: 1;
}

.filter-item.open .filter-item__icon {
  transform: rotate(45deg);
  color: var(--accent);
}

/* ===== Filter Content ===== */
.filter-item__content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.filter-item.open .filter-item__content {
  max-height: 400px;
  overflow-y: auto;
}

/* ===== Filter Search ===== */
.filter-search {
  padding: 0 20px 12px;
}

.filter-search__input {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 14px;
  font-family: var(--font);
  outline: none;
  transition: border-color var(--transition);
}

.filter-search__input:focus {
  border-color: var(--accent);
}

.filter-search__input::placeholder {
  color: var(--text-muted);
}

/* ===== Filter Options (checkboxes) ===== */
.filter-options {
  padding: 0 20px 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-options__empty {
  color: var(--text-muted);
  font-size: 14px;
  padding: 8px 0;
  width: 100%;
}

.filter-option {
  position: relative;
}

.filter-option input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.filter-option__label {
  display: inline-block;
  padding: 8px 16px;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-size: 14px;
  color: var(--text-primary);
  background: var(--bg-card);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.filter-option__label:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

.filter-option input:checked + .filter-option__label {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
  font-weight: 500;
}

/* ===== Filter Range ===== */
.filter-range {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 20px 16px;
}

.filter-range__group {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.filter-range__group label {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.filter-range__input,
.filter-range__select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 14px;
  font-family: var(--font);
  outline: none;
  transition: border-color var(--transition);
  -webkit-appearance: none;
  appearance: none;
}

.filter-range__select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%239ca3af' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}

.filter-range__input:focus,
.filter-range__select:focus {
  border-color: var(--accent);
}

.filter-range__separator {
  color: var(--text-muted);
  font-size: 16px;
  padding-top: 20px;
}

/* ===== Submit Button ===== */
.submit-area {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 16px 20px;
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  z-index: 100;
}

.submit-btn {
  width: 100%;
  padding: 14px;
  background: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: var(--radius);
  font-size: 16px;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 2px 8px rgba(255, 140, 0, 0.3);
}

.submit-btn:hover {
  background: var(--accent-hover);
  box-shadow: 0 4px 12px rgba(255, 140, 0, 0.4);
  transform: translateY(-1px);
}

.submit-btn:active {
  transform: translateY(0);
  box-shadow: 0 1px 4px rgba(255, 140, 0, 0.3);
}

.submit-btn:disabled {
  opacity: 0.5;
  pointer-events: none;
}

/* ===== FAB Phone Button ===== */
.fab-phone {
  position: fixed;
  bottom: 90px;
  right: 20px;
  width: 56px;
  height: 56px;
  background: var(--accent);
  color: #ffffff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(255, 140, 0, 0.4);
  z-index: 99;
  transition: all var(--transition);
  animation: fab-pulse 2s infinite;
}

.fab-phone:hover {
  background: var(--accent-hover);
  transform: scale(1.08);
  box-shadow: 0 6px 20px rgba(255, 140, 0, 0.5);
}

@keyframes fab-pulse {
  0%, 100% { box-shadow: 0 4px 16px rgba(255, 140, 0, 0.4); }
  50% { box-shadow: 0 4px 24px rgba(255, 140, 0, 0.6); }
}

/* ===== Scrollbar ===== */
.filter-item__content::-webkit-scrollbar {
  width: 4px;
}

.filter-item__content::-webkit-scrollbar-track {
  background: transparent;
}

.filter-item__content::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.filter-option {
  animation: fadeIn 0.2s ease forwards;
}

/* ===== Responsive ===== */
@media (max-width: 380px) {
  .filter-option__label {
    padding: 6px 12px;
    font-size: 13px;
  }

  .filter-item__header {
    padding: 14px 16px;
  }

  .filter-range,
  .filter-options,
  .filter-search {
    padding-left: 16px;
    padding-right: 16px;
  }
}