/* ===== CSS Variables ===== */
:root {
    --primary: #4f6ef7;
    --primary-hover: #3d5bd9;
    --primary-light: rgba(79, 110, 247, 0.08);
    --primary-lighter: rgba(79, 110, 247, 0.04);
    --text-primary: #1a1d26;
    --text-secondary: #5f6577;
    --text-muted: #9ca3b4;
    --bg-body: #f5f6f8;
    --bg-white: #ffffff;
    --bg-gray: #f0f1f4;
    --border: #e4e6eb;
    --border-light: #eceef2;
    --success: #22c55e;
    --warning: #f59e0b;
    --error: #ef4444;
    --radius: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.08);
    --transition: 0.2s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-body);
    -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }

/* ===== Layout ===== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

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

.header .container {
    display: flex;
    align-items: center;
    height: 60px;
    gap: 48px;
}

.logo {
    font-size: 20px;
    font-weight: 700;
    flex-shrink: 0;
}

.logo a {
    color: var(--primary);
    letter-spacing: -0.3px;
}

/* Navigation */
.nav {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav a {
    padding: 6px 14px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
}

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

.nav a.active {
    color: var(--primary);
    background: var(--primary-light);
    font-weight: 600;
}

/* User Menu */
.user-menu {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-left: auto;
    flex-shrink: 0;
}

.user-menu a {
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: var(--radius);
    transition: var(--transition);
}

.user-menu a:hover {
    color: var(--primary);
    background: var(--primary-light);
}

.user-menu .btn-login {
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.user-menu .btn-login:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}

.user-menu .btn-register {
    background: var(--primary);
    color: #fff;
    padding: 6px 16px;
    border-radius: var(--radius);
}

.user-menu .btn-register:hover {
    background: var(--primary-hover);
}

/* Points & Sign-in */
.points-badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
}

.btn-sign-in {
    padding: 5px 12px;
    background: var(--success);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-sign-in:hover:not(:disabled) {
    background: #16a34a;
}

.btn-sign-in:disabled {
    background: var(--bg-gray);
    color: var(--text-muted);
    cursor: not-allowed;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 8px;
}

.mobile-points {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.mobile-points .points-badge,
.mobile-points .btn-sign-in {
    margin-right: 0;
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    margin-left: auto;
    z-index: 110;
}

.menu-icon {
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 1px;
    transition: var(--transition);
}

.mobile-menu-btn.active .menu-icon:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.mobile-menu-btn.active .menu-icon:nth-child(2) { opacity: 0; }
.mobile-menu-btn.active .menu-icon:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* Mobile Menu */
.mobile-menu-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 105;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    right: -300px;
    width: 280px;
    height: 100vh;
    background: var(--bg-white);
    z-index: 110;
    padding: 24px;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.1);
    transition: right 0.3s ease;
    overflow-y: auto;
}

.mobile-menu.active { right: 0; }

.mobile-nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
    margin-bottom: 24px;
}

.mobile-nav a {
    padding: 12px 16px;
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
}

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

.mobile-user-menu {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
}

.mobile-user-menu a {
    padding: 12px 16px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    text-align: center;
    border-radius: var(--radius);
    transition: var(--transition);
}

.mobile-user-menu a:hover {
    background: var(--bg-gray);
    color: var(--primary);
}

/* ===== Main ===== */
.main {
    min-height: calc(100vh - 180px);
    padding: 32px 0;
}

/* ===== Footer ===== */
.footer {
    background: var(--text-primary);
    color: rgba(255, 255, 255, 0.5);
    padding: 32px 0;
    margin-top: 60px;
}

.footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.footer .logo { margin-bottom: 4px; }
.footer .logo a { color: var(--primary); }
.footer p { font-size: 13px; }
.footer-icp a { color: rgba(255, 255, 255, 0.5); text-decoration: none; font-size: 12px; }
.footer-icp a:hover { color: rgba(255, 255, 255, 0.8); }

.footer-links {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.4);
    font-size: 13px;
    transition: var(--transition);
}

.footer-links a:hover { color: rgba(255, 255, 255, 0.8); }

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    gap: 6px;
}

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

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

.btn-secondary {
    background: var(--bg-gray);
    color: var(--text-primary);
}

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

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

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

.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn-lg { padding: 12px 28px; font-size: 15px; }
.btn-block { width: 100%; }

/* ===== Cards ===== */
.card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.card:hover {
    border-color: var(--border);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.card-img-wrapper {
    position: relative;
    overflow: hidden;
    height: 0;
    padding-bottom: 60%;
}

.card-img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.card:hover .card-img {
    transform: scale(1.03);
}

.card-body {
    padding: 18px;
}

.card-title {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 6px;
    line-height: 1.4;
}

.card-title a {
    color: var(--text-primary);
    transition: var(--transition);
}

.card-title a:hover { color: var(--primary); }

.card-desc {
    color: var(--text-secondary);
    font-size: 13px;
    line-height: 1.5;
    margin-bottom: 10px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    font-size: 12px;
    color: var(--text-muted);
}

.card-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

/* Card Grid */
.card-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

/* ===== Tags ===== */
.tag {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    margin-right: 6px;
    margin-bottom: 6px;
}

.tag-primary { background: var(--primary-light); color: var(--primary); }
.tag-success { background: rgba(34, 197, 94, 0.1); color: var(--success); }
.tag-warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.tag-danger { background: rgba(239, 68, 68, 0.1); color: var(--error); }
.tag-php { background: rgba(124, 181, 236, 0.12); color: #4f5d95; }
.tag-frontend { background: rgba(82, 196, 26, 0.12); color: #389e0d; }
.tag-script { background: rgba(250, 173, 20, 0.12); color: #ad8b00; }
.tag-python { background: rgba(114, 46, 209, 0.12); color: #531dab; }
.tag-free { background: rgba(34, 197, 94, 0.1); color: var(--success); }
.tag-paid { background: rgba(239, 68, 68, 0.1); color: var(--error); }
.tag-points { background: rgba(245, 158, 11, 0.1); color: var(--warning); }

/* ===== Forms ===== */
.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.form-input {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-white);
    transition: var(--transition);
    outline: none;
}

.form-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.form-input::placeholder { color: var(--text-muted); }

.form-links {
    text-align: center;
    margin-top: 18px;
}

.form-links a {
    color: var(--primary);
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
}

.form-links a:hover { text-decoration: underline; }

/* ===== Search ===== */
.search-bar {
    background: var(--bg-white);
    padding: 20px 0;
    border-bottom: 1px solid var(--border);
}

.search-form {
    display: flex;
    max-width: 560px;
    margin: 0 auto;
    background: var(--bg-gray);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid transparent;
    transition: var(--transition);
}

.search-form:focus-within {
    background: var(--bg-white);
    border-color: var(--primary);
}

.search-input {
    flex: 1;
    padding: 12px 18px;
    border: none;
    font-size: 14px;
    background: transparent;
    outline: none;
    color: var(--text-primary);
}

.search-input::placeholder { color: var(--text-muted); }

.search-form .btn-primary {
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    padding: 12px 24px;
    font-weight: 600;
}

/* ===== Filter Tabs ===== */
.filter-section {
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
    background: var(--bg-white);
}

.filter-tabs {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.filter-tabs a {
    padding: 6px 16px;
    border-radius: 8px;
    background: var(--bg-gray);
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    transition: var(--transition);
}

.filter-tabs a:hover { background: var(--primary-light); color: var(--primary); }
.filter-tabs a.active { background: var(--primary); color: #fff; }

/* ===== Pagination ===== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 6px;
    margin-top: 36px;
}

.pagination a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
    min-width: 40px;
}

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

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

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: 60px 0;
}

.empty-state .icon-empty {
    font-size: 64px;
    color: var(--text-muted);
    opacity: 0.4;
    margin-bottom: 16px;
}

.empty-state p {
    color: var(--text-muted);
    font-size: 15px;
}

/* ===== Download Modal ===== */
.download-modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.download-modal-overlay.active { display: flex; opacity: 1; }

.download-modal {
    background: var(--bg-white);
    border-radius: var(--radius-xl);
    padding: 32px;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    transform: scale(0.95);
    transition: transform 0.3s ease;
}

.download-modal-overlay.active .download-modal { transform: scale(1); }

.modal-header { text-align: center; margin-bottom: 20px; }

.modal-icon {
    width: 56px;
    height: 56px;
    background: var(--primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 14px;
    font-size: 24px;
    color: var(--primary);
}

.modal-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 6px;
}

.modal-desc {
    font-size: 13px;
    color: var(--text-secondary);
}

.modal-info {
    background: var(--bg-gray);
    border-radius: var(--radius);
    padding: 16px;
    margin-bottom: 20px;
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: 6px 0;
    border-bottom: 1px dashed var(--border);
}

.info-row:last-child { border-bottom: none; }

.info-label { font-size: 13px; color: var(--text-secondary); }
.info-value { font-size: 13px; font-weight: 600; }
.info-value.points { color: var(--warning); }
.info-value.balance { color: var(--success); }

.modal-warning {
    background: rgba(251, 191, 36, 0.08);
    border-left: 3px solid var(--warning);
    padding: 10px 14px;
    margin-bottom: 20px;
    font-size: 13px;
    color: #92400e;
    border-radius: 0 var(--radius) var(--radius) 0;
}

.modal-actions {
    display: flex;
    gap: 10px;
}

.modal-actions .btn {
    flex: 1;
    padding: 12px;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius);
}

.modal-actions .btn-cancel { background: var(--bg-gray); color: var(--text-secondary); }
.modal-actions .btn-cancel:hover { background: var(--border); }
.modal-actions .btn-confirm { background: var(--primary); color: #fff; }
.modal-actions .btn-confirm:hover:not(:disabled) { background: var(--primary-hover); }
.modal-actions .btn:disabled { opacity: 0.5; cursor: not-allowed; }
.modal-actions .btn-task {
    background: var(--warning, #f59e0b);
    color: #fff;
    text-decoration: none;
    text-align: center;
    display: none;
    align-items: center;
    justify-content: center;
}
.modal-actions .btn-task:hover { opacity: 0.9; }

/* ===== Toast ===== */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 20px;
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    animation: toastIn 0.3s ease-out;
    max-width: 360px;
}

@keyframes toastIn {
    from { opacity: 0; transform: translateX(100%); }
    to { opacity: 1; transform: translateX(0); }
}

.toast-success { background: var(--success); color: #fff; }
.toast-error { background: var(--error); color: #fff; }
.toast-info { background: var(--primary); color: #fff; }
.toast-icon { font-size: 18px; flex-shrink: 0; }
.toast-message { flex: 1; font-size: 14px; font-weight: 500; }
.toast-close {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: #fff;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
}

/* ===== Responsive ===== */
@media (max-width: 1200px) {
    .container { padding: 0 32px; }
}

@media (max-width: 1024px) {
    .card-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
}

@media (max-width: 768px) {
    .container { padding: 0 16px; }

    .header .container { height: 54px; gap: 0; }
    .logo { font-size: 18px; }

    .nav, .user-menu { display: none !important; }
    .mobile-menu-btn { display: flex; }
    .mobile-menu-overlay, .mobile-menu { display: block; }

    .card-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }

    .hero-banner h1 { font-size: 28px; }
    .hero-banner p { font-size: 15px; }
    .hero-buttons { flex-direction: column; align-items: center; gap: 10px; }

    .features-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }

    .section-header h2 { font-size: 22px; }

    .footer { padding: 24px 0; }
    .footer-links { gap: 12px; }
}

@media (max-width: 480px) {
    .container { padding: 0 12px; }
    .main { padding: 20px 0; }

    .card-grid { grid-template-columns: 1fr; gap: 10px; }

    .card-body { padding: 14px; }
    .card-title { font-size: 15px; }
    .card-desc { font-size: 12px; }
    .card-meta { font-size: 11px; gap: 10px; }

    .hero-banner { padding: 40px 0; }
    .hero-banner h1 { font-size: 24px; }

    .btn-lg { padding: 10px 20px; font-size: 14px; }

    .filter-tabs { gap: 6px; }
    .filter-tabs a { padding: 5px 10px; font-size: 12px; }

    .search-form { flex-direction: column; gap: 8px; background: transparent; border: none; }
    .search-input { border-radius: var(--radius); border: 1px solid var(--border); background: var(--bg-white); padding: 10px 14px; }
    .search-form .btn-primary { border-radius: var(--radius); width: 100%; }

    .pagination a { padding: 6px 10px; font-size: 13px; min-width: 34px; }

    .footer p { font-size: 12px; }
}