/* ========================================
   工程计算库 - 全局样式
   工程规范查询 + 在线计算工具
======================================== */

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

:root {
    --primary: #1a5fb4;
    --primary-light: #e8f0fa;
    --primary-dark: #0c447c;
    --success: #0d7d4d;
    --success-light: #e8f5ee;
    --warning: #d97706;
    --warning-light: #fef3e7;
    --danger: #dc2626;
    --danger-light: #fef2f2;
    --text-primary: #1a1a2e;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --bg-page: #f5f6f8;
    --bg-card: #ffffff;
    --border: #e5e7eb;
    --border-hover: #d1d5db;
    --radius: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 2px 8px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    --max-width: 1200px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue",
                 Helvetica, Arial, sans-serif;
    background: var(--bg-page);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.15s;
}

a:hover {
    color: var(--primary-dark);
}

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

/* ========== Header ========== */
.site-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    height: 60px;
    gap: 32px;
}

.logo {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
    letter-spacing: 1px;
}

.logo .logo-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--primary);
    color: #fff;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 700;
}

.main-nav {
    display: flex;
    gap: 4px;
    align-items: center;
}

.main-nav a {
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    padding: 8px 14px;
    border-radius: var(--radius);
    transition: all 0.15s;
}

.main-nav a:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.main-nav a.active {
    background: var(--primary-light);
    color: var(--primary);
}

.header-search {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-search input {
    width: 200px;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 13px;
    outline: none;
    transition: border-color 0.15s;
}

.header-search input:focus {
    border-color: var(--primary);
}

.header-search button {
    padding: 8px 16px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-size: 13px;
    cursor: pointer;
    font-weight: 500;
    transition: background 0.15s;
}

.header-search button:hover {
    background: var(--primary-dark);
}

/* ========== Main Content ========== */
.main-content {
    flex: 1;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 32px 20px;
    width: 100%;
}

/* ========== Hero Section ========== */
.hero {
    text-align: center;
    padding: 48px 20px 40px;
}

.hero h1 {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    line-height: 1.3;
}

.hero .subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 28px;
}

.hero-search {
    max-width: 560px;
    margin: 0 auto;
    display: flex;
    gap: 8px;
}

.hero-search input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 15px;
    outline: none;
    transition: border-color 0.15s;
}

.hero-search input:focus {
    border-color: var(--primary);
}

.hero-search button {
    padding: 12px 28px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-size: 15px;
    cursor: pointer;
    font-weight: 500;
    transition: background 0.15s;
    white-space: nowrap;
}

.hero-search button:hover {
    background: var(--primary-dark);
}

.hero-tags {
    margin-top: 16px;
    display: flex;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
}

.hero-tags a {
    font-size: 13px;
    color: var(--text-secondary);
    padding: 4px 12px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    transition: all 0.15s;
}

.hero-tags a:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* ========== Section ========== */
.section {
    margin-bottom: 40px;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.section-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
}

.section-header a {
    font-size: 14px;
    color: var(--primary);
}

/* ========== Card Grid ========== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
}

.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    transition: all 0.2s;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

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

.tool-card .card-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    margin-bottom: 4px;
}

.tool-card .card-icon.blue {
    background: var(--primary-light);
    color: var(--primary);
}

.tool-card .card-icon.green {
    background: var(--success-light);
    color: var(--success);
}

.tool-card .card-icon.amber {
    background: var(--warning-light);
    color: var(--warning);
}

.tool-card h3 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
}

.tool-card p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.tool-card .card-tag {
    font-size: 12px;
    color: var(--success);
    margin-top: auto;
}

/* ========== Standards List ========== */
.standards-layout {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: 24px;
    align-items: start;
}

.sidebar-filter {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 16px;
    position: sticky;
    top: 80px;
}

.sidebar-filter h3 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.filter-group {
    margin-bottom: 20px;
}

.filter-group h4 {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.filter-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 0;
    cursor: pointer;
    font-size: 13px;
    color: var(--text-secondary);
    transition: color 0.15s;
}

.filter-item:hover {
    color: var(--primary);
}

.filter-item input[type="checkbox"] {
    accent-color: var(--primary);
}

.filter-item .count {
    margin-left: auto;
    font-size: 12px;
    color: var(--text-tertiary);
}

/* Standards List */
.standards-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.standard-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: border-color 0.15s;
}

.standard-item:hover {
    border-color: var(--border-hover);
}

.standard-header {
    padding: 16px 20px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    cursor: pointer;
}

.standard-code {
    display: inline-block;
    padding: 3px 8px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    white-space: nowrap;
    flex-shrink: 0;
}

.standard-title {
    flex: 1;
}

.standard-title h3 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.standard-meta {
    font-size: 12px;
    color: var(--text-tertiary);
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.standard-expand {
    color: var(--text-tertiary);
    font-size: 13px;
    flex-shrink: 0;
    margin-top: 2px;
}

.standard-body {
    display: none;
    padding: 0 20px 16px;
    border-top: 1px solid var(--border);
    margin-top: 4px;
}

.standard-body.open {
    display: block;
}

.standard-body .clause {
    padding: 12px 0;
    border-bottom: 1px dashed var(--border);
}

.standard-body .clause:last-child {
    border-bottom: none;
}

.standard-body .clause-num {
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 4px;
}

.standard-body .clause-text {
    font-size: 13px;
    color: var(--text-primary);
    line-height: 1.7;
}

.standard-body .clause-text mark {
    background: #fff3a0;
    padding: 0 2px;
    border-radius: 2px;
}

/* ========== Calculators ========== */
.calc-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 24px;
    align-items: start;
}

.calc-sidebar {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 12px;
    position: sticky;
    top: 80px;
}

.calc-sidebar h3 {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-tertiary);
    padding: 8px 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.calc-nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 14px;
    color: var(--text-secondary);
    transition: all 0.15s;
}

.calc-nav-item:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.calc-nav-item.active {
    background: var(--primary-light);
    color: var(--primary);
    font-weight: 500;
}

.calc-nav-item .nav-icon {
    font-size: 18px;
    width: 24px;
    text-align: center;
}

.calc-panel {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
}

.calc-panel-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}

.calc-panel-desc {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.calc-form {
    display: grid;
    gap: 16px;
}

.calc-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.calc-field {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.calc-field label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
}

.calc-field label .unit {
    font-weight: 400;
    color: var(--text-tertiary);
    font-size: 12px;
}

.calc-field input,
.calc-field select {
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    outline: none;
    transition: border-color 0.15s;
    background: var(--bg-card);
}

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

.calc-field .hint {
    font-size: 12px;
    color: var(--text-tertiary);
}

.calc-actions {
    display: flex;
    gap: 12px;
    margin-top: 4px;
}

.btn-primary {
    padding: 10px 32px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s;
}

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

.btn-secondary {
    padding: 10px 24px;
    background: var(--bg-card);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    cursor: pointer;
    transition: all 0.15s;
}

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

.calc-result {
    margin-top: 24px;
    padding: 20px;
    background: var(--success-light);
    border: 1px solid #c8e6d4;
    border-radius: var(--radius-lg);
    display: none;
}

.calc-result.show {
    display: block;
}

.calc-result .result-label {
    font-size: 13px;
    color: var(--success);
    font-weight: 500;
    margin-bottom: 4px;
}

.calc-result .result-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
}

.calc-result .result-value .result-unit {
    font-size: 16px;
    font-weight: 400;
    color: var(--text-secondary);
    margin-left: 4px;
}

.calc-result .result-detail {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid #c8e6d4;
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.calc-result .result-detail .detail-row {
    display: flex;
    justify-content: space-between;
}

.calc-formula {
    margin-top: 20px;
    padding: 16px;
    background: #f8f9fa;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.calc-formula .formula-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.calc-formula code {
    font-family: "Cascadia Code", Consolas, "Courier New", monospace;
    font-size: 13px;
    background: #eef1f5;
    padding: 2px 6px;
    border-radius: 3px;
    color: var(--primary-dark);
}

/* Quick stats */
.quick-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    text-align: center;
}

.stat-card .stat-num {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary);
}

.stat-card .stat-label {
    font-size: 13px;
    color: var(--text-secondary);
    margin-top: 4px;
}

/* Category nav */
.category-nav {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-bottom: 32px;
}

.category-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px 16px;
    text-align: center;
    transition: all 0.15s;
    cursor: pointer;
}

.category-card:hover {
    border-color: var(--primary);
    background: var(--primary-light);
}

.category-card .cat-icon {
    font-size: 28px;
    margin-bottom: 8px;
}

.category-card .cat-name {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
}

.category-card .cat-count {
    font-size: 12px;
    color: var(--text-tertiary);
    margin-top: 2px;
}

/* ========== Footer ========== */
.site-footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 32px 20px;
    margin-top: auto;
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    font-size: 13px;
    color: var(--text-secondary);
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-copy {
    font-size: 13px;
    color: var(--text-tertiary);
}

/* ========== Breadcrumb ========== */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-tertiary);
    margin-bottom: 20px;
}

.breadcrumb a {
    color: var(--text-secondary);
}

.breadcrumb span {
    color: var(--text-tertiary);
}

/* ========== Empty State ========== */
.empty-state {
    text-align: center;
    padding: 48px 20px;
    color: var(--text-tertiary);
}

.empty-state .empty-icon {
    font-size: 48px;
    margin-bottom: 12px;
    opacity: 0.4;
}

/* ========== Responsive ========== */
@media (max-width: 900px) {
    .standards-layout,
    .calc-layout {
        grid-template-columns: 1fr;
    }

    .sidebar-filter,
    .calc-sidebar {
        position: static;
    }

    .calc-sidebar {
        display: flex;
        flex-wrap: wrap;
        gap: 4px;
    }

    .calc-sidebar h3 {
        width: 100%;
    }

    .calc-nav-item {
        flex: 1;
        justify-content: center;
        padding: 8px 12px;
    }

    .header-search {
        display: none;
    }
}

@media (max-width: 600px) {
    .hero h1 {
        font-size: 24px;
    }

    .hero {
        padding: 32px 16px 24px;
    }

    .hero-search {
        flex-direction: column;
    }

    .hero-search input {
        width: 100%;
    }

    .calc-row {
        grid-template-columns: 1fr;
    }

    .main-nav {
        gap: 0;
    }

    .main-nav a {
        padding: 8px 8px;
        font-size: 13px;
    }

    .header-inner {
        gap: 12px;
    }
}

/* ========================================
   后台管理 Admin Styles
======================================== */

/* Login */
.admin-login-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow);
}

.admin-login-input:focus {
    border-color: var(--primary) !important;
}

/* Toolbar */
.admin-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 20px;
}

.admin-toolbar-actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.admin-toolbar-actions .btn-secondary {
    padding: 8px 16px;
    font-size: 13px;
}

.admin-import-btn {
    position: relative;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
}

/* Messages */
.admin-msg {
    padding: 10px 16px;
    border-radius: var(--radius);
    font-size: 13px;
    margin-bottom: 16px;
}

.admin-msg.success {
    background: var(--success-light);
    border: 1px solid #c8e6d4;
    color: var(--success);
}

.admin-msg.error {
    background: var(--danger-light);
    border: 1px solid #f0c5c5;
    color: var(--danger);
}

.admin-msg.info {
    background: var(--primary-light);
    border: 1px solid #c4d4e8;
    color: var(--primary);
}

/* Table */
.admin-table-wrap {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow-x: auto;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
}

.admin-table thead th {
    background: var(--bg-page);
    padding: 12px 16px;
    text-align: left;
    font-weight: 500;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

.admin-table tbody td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
    color: var(--text-primary);
    vertical-align: middle;
}

.admin-table tbody tr:last-child td {
    border-bottom: none;
}

.admin-table tbody tr:hover {
    background: var(--primary-light);
}

.admin-code {
    display: inline-block;
    padding: 3px 8px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    white-space: nowrap;
}

.admin-empty {
    text-align: center !important;
    color: var(--text-tertiary) !important;
    padding: 48px 16px !important;
}

/* Small buttons */
.btn-sm {
    padding: 5px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    background: var(--bg-card);
    color: var(--text-secondary);
    transition: all 0.15s;
    white-space: nowrap;
}

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

.btn-edit {
    color: var(--primary);
    border-color: var(--primary);
}

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

.btn-del {
    color: var(--danger);
    border-color: var(--danger);
    margin-left: 4px;
}

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

.admin-actions {
    white-space: nowrap;
}

/* Form */
.admin-form {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
}

.admin-form-section {
    margin-bottom: 28px;
}

.admin-form-section h3 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

/* Clause edit rows */
.clause-edit-row {
    display: grid;
    grid-template-columns: 140px 1fr 36px;
    gap: 12px;
    margin-bottom: 12px;
    align-items: flex-start;
}

.clause-num-input {
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    outline: none;
    transition: border-color 0.15s;
}

.clause-num-input:focus {
    border-color: var(--primary);
}

.clause-text-input {
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    outline: none;
    transition: border-color 0.15s;
    resize: vertical;
    font-family: inherit;
    line-height: 1.6;
    min-height: 60px;
}

.clause-text-input:focus {
    border-color: var(--primary);
}

.clause-edit-row .btn-sm {
    margin-top: 4px;
    width: 36px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

/* Admin responsive */
@media (max-width: 700px) {
    .admin-toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    .admin-toolbar-actions {
        justify-content: center;
    }

    .clause-edit-row {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .clause-edit-row .btn-sm {
        width: 100%;
        height: 32px;
    }

    .admin-form {
        padding: 16px;
    }

    .admin-table {
        font-size: 12px;
    }

    .admin-table thead th,
    .admin-table tbody td {
        padding: 8px 10px;
    }
}

/* Logo image styles */
.logo-img {
    height: 28px;
    max-width: 40px;
    width: auto;
    display: block;
    object-fit: contain;
    border-radius: var(--radius);
    flex-shrink: 0;
}
.logo-text {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 1px;
    white-space: nowrap;
}