/* ═══════════════════════════════════════════════
   EduVault — styles.css
   Educational Resource Website Stylesheet
═══════════════════════════════════════════════ */

/* ─── GOOGLE FONTS ─── */
@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;600;700;800&family=DM+Sans:ital,wght@0,300;0,400;0,500;1,300&display=swap');

/* ─── CSS VARIABLES ─── */
:root {
    --bg: #0a0a12;
    --surface: #13131f;
    --surface2: #1c1c2e;
    --border: #2a2a40;
    --accent: #6c63ff;
    --accent2: #ff6584;
    --accent3: #43e97b;
    --text: #e8e8f0;
    --muted: #7070a0;
    --radius: 16px;
    --shadow: 0 20px 60px rgba(108, 99, 255, 0.2);
    --font-head: 'Syne', sans-serif;
    --font-body: 'DM Sans', sans-serif;
}

/* ═══════════════════════════════
   RESET & BASE
═══════════════════════════════ */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Ambient background glow */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 20% 10%, rgba(108, 99, 255, 0.12) 0%, transparent 60%),
        radial-gradient(ellipse 60% 50% at 80% 80%, rgba(255, 101, 132, 0.08) 0%, transparent 60%);
    pointer-events: none;
    z-index: 0;
}

/* ═══════════════════════════════
   NAVIGATION
═══════════════════════════════ */
nav {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 40px;
    background: rgba(10, 10, 18, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}

.logo {
    font-family: var(--font-head);
    font-weight: 800;
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    letter-spacing: -0.02em;
}

.nav-tabs {
    display: flex;
    gap: 6px;
    background: var(--surface2);
    padding: 6px;
    border-radius: 50px;
    border: 1px solid var(--border);
}

.nav-tab {
    padding: 8px 22px;
    border-radius: 50px;
    border: none;
    background: transparent;
    color: var(--muted);
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.3s, color 0.3s;
}

.nav-tab.active {
    background: var(--accent);
    color: #fff;
}

.nav-tab:hover:not(.active) {
    color: var(--text);
}

/* ═══════════════════════════════
   PAGE SYSTEM
═══════════════════════════════ */
.page {
    display: none;
    position: relative;
    z-index: 1;
}

.page.active {
    display: block;
    animation: fadeUp 0.4s ease both;
}

/* ═══════════════════════════════
   ANIMATIONS
═══════════════════════════════ */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(14px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

/* ═══════════════════════════════
   HERO SECTION
═══════════════════════════════ */
.hero {
    padding: 80px 40px 60px;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    padding: 6px 18px;
    border-radius: 50px;
    background: rgba(108, 99, 255, 0.15);
    border: 1px solid rgba(108, 99, 255, 0.4);
    color: #a89fff;
    font-size: 0.78rem;
    font-weight: 600;
    margin-bottom: 22px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.hero h1 {
    font-family: var(--font-head);
    font-size: clamp(2.4rem, 6vw, 5rem);
    font-weight: 800;
    line-height: 1.05;
    margin-bottom: 20px;
    letter-spacing: -0.03em;
}

.hero h1 .gradient-text {
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    color: var(--muted);
    font-size: 1.1rem;
    max-width: 520px;
    margin: 0 auto 36px;
    line-height: 1.75;
    font-weight: 300;
}

/* ─── SEARCH BAR ─── */
.search-wrap {
    max-width: 560px;
    margin: 0 auto 50px;
    position: relative;
}

.search-wrap input {
    width: 100%;
    padding: 16px 56px 16px 22px;
    border-radius: 50px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.search-wrap input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px rgba(108, 99, 255, 0.15);
}

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

.search-icon {
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--muted);
    pointer-events: none;
    font-size: 1.1rem;
}

/* ─── FILTER PILLS ─── */
.filter-row {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 48px;
}

.filter-pill {
    padding: 8px 20px;
    border-radius: 50px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--muted);
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: border-color 0.25s, color 0.25s, background 0.25s;
}

.filter-pill:hover {
    border-color: rgba(108, 99, 255, 0.5);
    color: var(--text);
}

.filter-pill.active {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(108, 99, 255, 0.1);
}

/* ═══════════════════════════════
   RESOURCE GRID
═══════════════════════════════ */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    padding: 0 40px 80px;
    max-width: 1400px;
    margin: 0 auto;
}

/* ─── CARD ─── */
.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
    animation: fadeUp 0.5s ease both;
}

.card:hover {
    transform: translateY(-7px);
    border-color: var(--accent);
    box-shadow: var(--shadow);
}

.card-thumb {
    width: 100%;
    height: 180px;
    object-fit: cover;
    display: block;
    background: var(--surface2);
    transition: transform 0.4s;
}

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

.card-thumb-wrap {
    overflow: hidden;
    height: 180px;
}

/* PDF placeholder thumb */
.card-pdf-thumb {
    width: 100%;
    height: 180px;
    background: linear-gradient(135deg, var(--surface2) 0%, #222240 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 10px;
    transition: opacity 0.3s;
}

.card:hover .card-pdf-thumb {
    opacity: 0.85;
}

.card-pdf-thumb .pdf-icon-lg {
    font-size: 3rem;
}

.card-pdf-thumb span {
    font-size: 0.78rem;
    color: var(--muted);
    max-width: 180px;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Card body */
.card-body {
    padding: 18px 20px 20px;
}

.card-type {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 3px 10px;
    border-radius: 50px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    margin-bottom: 10px;
}

.type-image {
    background: rgba(67, 233, 123, 0.12);
    color: #43e97b;
}

.type-pdf {
    background: rgba(255, 101, 132, 0.12);
    color: #ff6584;
}

.card-title {
    font-family: var(--font-head);
    font-weight: 700;
    font-size: 1.05rem;
    margin-bottom: 7px;
    line-height: 1.3;
    letter-spacing: -0.01em;
}

.card-desc {
    font-size: 0.83rem;
    color: var(--muted);
    line-height: 1.55;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.78rem;
    color: var(--muted);
}

.card-category {
    display: inline-block;
    padding: 3px 9px;
    border-radius: 6px;
    background: var(--surface2);
    font-size: 0.72rem;
    font-weight: 500;
}

.btn-view {
    padding: 7px 16px;
    border-radius: 50px;
    background: var(--accent);
    color: #fff;
    border: none;
    font-family: var(--font-body);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.2s;
    letter-spacing: 0.02em;
}

.btn-view:hover {
    opacity: 0.85;
    transform: translateX(2px);
}

/* Empty state */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 90px 20px;
    color: var(--muted);
}

.empty-state .icon {
    font-size: 4rem;
    margin-bottom: 16px;
    display: block;
}

.empty-state p {
    font-size: 1rem;
    line-height: 1.6;
}

/* ═══════════════════════════════
   ADMIN DASHBOARD
═══════════════════════════════ */
.admin-wrap {
    max-width: 820px;
    margin: 0 auto;
    padding: 60px 40px 80px;
}

.admin-header {
    margin-bottom: 40px;
}

.admin-header h2 {
    font-family: var(--font-head);
    font-size: 2.2rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 8px;
}

.admin-header p {
    color: var(--muted);
    font-size: 0.95rem;
}

/* Stats row */
.stats-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 36px;
}

.stat-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px;
    text-align: center;
    transition: border-color 0.3s;
}

.stat-card:hover {
    border-color: var(--accent);
}

.stat-num {
    font-family: var(--font-head);
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
    line-height: 1;
    margin-bottom: 6px;
}

.stat-label {
    font-size: 0.78rem;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.07em;
    font-weight: 500;
}

/* Upload area */
.upload-area {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 60px 40px;
    text-align: center;
    cursor: pointer;
    background: var(--surface);
    position: relative;
    transition: border-color 0.3s, background 0.3s;
    margin-bottom: 28px;
}

.upload-area:hover,
.upload-area.drag-over {
    border-color: var(--accent);
    background: rgba(108, 99, 255, 0.06);
}

.upload-area input[type="file"] {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
    width: 100%;
    height: 100%;
}

.upload-icon-lg {
    font-size: 3.2rem;
    margin-bottom: 14px;
    display: block;
}

.upload-area h3 {
    font-family: var(--font-head);
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.upload-area p {
    color: var(--muted);
    font-size: 0.88rem;
}

/* Preview box */
.preview-box {
    display: none;
    margin-bottom: 22px;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--border);
    animation: slideDown 0.3s ease;
}

.preview-box img {
    width: 100%;
    max-height: 230px;
    object-fit: cover;
    display: block;
}

.preview-pdf {
    padding: 20px;
    background: var(--surface2);
    display: flex;
    align-items: center;
    gap: 14px;
}

.preview-pdf .pdf-icon {
    font-size: 2rem;
}

.preview-pdf .pdf-name {
    font-size: 0.9rem;
    color: var(--muted);
}

.preview-pdf .pdf-size {
    font-size: 0.78rem;
    color: rgba(112, 112, 160, 0.7);
}

/* Form groups */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.07em;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 13px 16px;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.3s, box-shadow 0.3s;
    appearance: none;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.12);
}

.form-group textarea {
    resize: vertical;
    min-height: 95px;
    line-height: 1.6;
}

.form-group select {
    cursor: pointer;
}

.form-group select option {
    background: var(--surface2);
}

/* Submit button */
.btn-submit {
    width: 100%;
    padding: 16px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--accent), #8b7fff);
    color: #fff;
    border: none;
    font-family: var(--font-head);
    font-size: 1.05rem;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.25s, transform 0.2s;
    letter-spacing: 0.02em;
}

.btn-submit:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

.btn-submit:active {
    transform: translateY(0);
}

/* ─── Admin items list ─── */
.admin-items {
    margin-top: 50px;
}

.admin-items-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.admin-items-header h3 {
    font-family: var(--font-head);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.07em;
}

.admin-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 16px;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: var(--surface);
    margin-bottom: 10px;
    transition: border-color 0.25s, background 0.25s;
    animation: slideDown 0.3s ease both;
}

.admin-item:hover {
    border-color: rgba(108, 99, 255, 0.4);
}

.admin-item-thumb {
    width: 58px;
    height: 58px;
    border-radius: 10px;
    overflow: hidden;
    flex-shrink: 0;
    background: var(--surface2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
}

.admin-item-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.admin-item-info {
    flex: 1;
    min-width: 0;
}

.admin-item-info strong {
    display: block;
    font-size: 0.92rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 3px;
}

.admin-item-info span {
    font-size: 0.77rem;
    color: var(--muted);
}

.btn-delete {
    padding: 7px 15px;
    border-radius: 8px;
    border: 1px solid rgba(255, 101, 132, 0.3);
    background: rgba(255, 101, 132, 0.07);
    color: var(--accent2);
    font-family: var(--font-body);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    flex-shrink: 0;
    transition: background 0.2s, transform 0.15s;
}

.btn-delete:hover {
    background: rgba(255, 101, 132, 0.18);
    transform: scale(1.03);
}

/* ═══════════════════════════════
   MODAL
═══════════════════════════════ */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 500;
    background: rgba(0, 0, 0, 0.82);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    display: none;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal-overlay.open {
    display: flex;
    animation: fadeIn 0.25s ease;
}

.modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 22px;
    max-width: 920px;
    width: 100%;
    max-height: 90vh;
    overflow: hidden;
    animation: fadeUp 0.3s ease;
    display: flex;
    flex-direction: column;
}

.modal-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 26px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.modal-top h3 {
    font-family: var(--font-head);
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.01em;
}

.modal-close {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--muted);
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s, color 0.2s;
}

.modal-close:hover {
    background: var(--surface2);
    color: var(--text);
}

.modal-body {
    padding: 26px;
    overflow-y: auto;
    flex: 1;
}

.modal-body img {
    width: 100%;
    border-radius: 14px;
    max-height: 500px;
    object-fit: contain;
    background: var(--surface2);
}

.modal-body iframe {
    width: 100%;
    height: 500px;
    border-radius: 12px;
    border: 1px solid var(--border);
    display: block;
}

.modal-desc {
    margin-top: 18px;
    font-size: 0.93rem;
    color: var(--muted);
    line-height: 1.75;
}

.modal-desc strong {
    color: var(--text);
    font-weight: 600;
}

/* PDF placeholder in modal */
.modal-pdf-placeholder {
    text-align: center;
    padding: 60px 20px;
}

.modal-pdf-placeholder .big-icon {
    font-size: 5.5rem;
    margin-bottom: 18px;
    display: block;
}

.modal-pdf-placeholder h4 {
    font-family: var(--font-head);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.modal-pdf-placeholder p {
    color: var(--muted);
    font-size: 0.88rem;
}

/* ═══════════════════════════════
   TOAST NOTIFICATION
═══════════════════════════════ */
.toast {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
    background: var(--surface2);
    border: 1px solid var(--accent3);
    border-radius: 14px;
    padding: 14px 24px;
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--accent3);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.35s, transform 0.35s;
    pointer-events: none;
    max-width: 320px;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

/* ═══════════════════════════════
   SCROLLBAR STYLING
═══════════════════════════════ */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--surface);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent);
}

/* ═══════════════════════════════
   RESPONSIVE
═══════════════════════════════ */
@media (max-width: 768px) {
    nav {
        padding: 14px 20px;
    }

    .hero {
        padding: 50px 20px 40px;
    }

    .grid {
        padding: 0 20px 60px;
        gap: 16px;
    }

    .admin-wrap {
        padding: 40px 20px 60px;
    }

    .stats-row {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .upload-area {
        padding: 40px 20px;
    }
}

@media (max-width: 480px) {
    .nav-tab {
        padding: 7px 12px;
        font-size: 0.8rem;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .toast {
        right: 16px;
        bottom: 16px;
        left: 16px;
    }

    .modal {
        border-radius: 16px;
    }
}