/* ─────────────────────────────────────────────
   Mnemonics Page — CATKing
   Design based on provided reference
───────────────────────────────────────────── */

:root {
    --orange:    #FEA525;
    --orange-dk: #E8931A;
    --ink:       #0F1021;
    --white:     #ffffff;
    --line:      #E8E8E8;
    --muted:     #BFBAB2;
    --bg:        #F7F6F3;
}

.mnemonics-page {
    font-family: 'DM Sans', sans-serif;
    background: #fff;
    color: #333;
    -webkit-font-smoothing: antialiased;
}

.section-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
}

/* ══════════════════════════════════════════
   HERO
══════════════════════════════════════════ */
.mnemonics-hero {
    background: var(--ink);
    padding: 80px 0;
    position: relative;
    overflow: hidden;
    color: var(--white);
    text-align: left;
}

.mnemonics-hero::before {
    content: '';
    position: absolute;
    left: -100px; top: -100px;
    width: 400px; height: 400px;
    background: radial-gradient(circle, #4B3621 0%, transparent 70%);
    border-radius: 50%;
    opacity: 0.4;
}

.mnemonics-hero::after {
    content: '';
    position: absolute;
    right: -100px; bottom: -100px;
    width: 400px; height: 400px;
    background: radial-gradient(circle, #0D3D2F 0%, transparent 70%);
    border-radius: 50%;
    opacity: 0.5;
}

.mnemonics-hero .hero-content {
    position: relative;
    z-index: 5;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.mnemonics-hero h1 {
    font-size: 52px;
    font-weight: 800;
    margin: 0;
}

.mnemonics-hero .hero-image {
    flex: 0 0 350px;
}

.image-placeholder {
    width: 100%;
    aspect-ratio: 1.5 / 1;
    border: 1px dashed rgba(255,255,255,0.2);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255,255,255,0.03);
    font-size: 11px;
    color: rgba(255,255,255,0.3);
    text-align: center;
    padding: 20px;
}

/* ══════════════════════════════════════════
   LISTING
══════════════════════════════════════════ */
.mnemonics-listing {
    padding: 80px 0;
}

.mnemonics-listing h2 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 12px;
    color: var(--ink);
}

.mnemonics-listing .subtitle {
    font-size: 16px;
    color: #666;
    max-width: 800px;
    line-height: 1.6;
    margin-bottom: 50px;
}

.mnemonics-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.mnemonic-card {
    background: #fff;
    border-radius: 12px;
    border: 1px solid #eee;
    overflow: hidden;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.mnemonic-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    border-color: var(--orange);
}

.card-img {
    width: 100%;
    aspect-ratio: 1.6 / 1;
    background: #f0f4f8; /* Default light blue bg as seen in SS */
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

/* Cycle colors for illustration bg if no image */
.mnemonic-card:nth-child(4n+1) .card-img { background: #e8f0fe; }
.mnemonic-card:nth-child(4n+2) .card-img { background: #e0f2f1; }
.mnemonic-card:nth-child(4n+3) .card-img { background: #fff3e0; }
.mnemonic-card:nth-child(4n+4) .card-img { background: #f3e5f5; }

.card-img span {
    font-size: 12px;
    color: #999;
    font-style: italic;
}

.card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.card-body {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-body h3 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.4;
    color: var(--ink);
    min-height: 45px;
}

.btn-read {
    display: inline-block;
    padding: 8px 20px;
    background: var(--orange);
    color: var(--ink);
    font-weight: 800;
    font-size: 13px;
    border-radius: 6px;
    text-decoration: none;
    align-self: flex-start;
    transition: background 0.2s;
}

.btn-read:hover {
    background: var(--orange-dk);
}

.grid-footer {
    margin-top: 50px;
    padding: 20px;
    background: #fdfdfd;
    border: 1px dashed #eee;
    border-radius: 10px;
    text-align: center;
    font-size: 13px;
    color: #999;
}

/* ══════════════════════════════════════════
   DETAIL PAGE
══════════════════════════════════════════ */
.mnemonic-detail {
    padding: 60px 0 100px;
}

.mnemonic-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 60px;
    align-items: start;
}

.detail-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 40px;
    gap: 20px;
}

.detail-header h2 {
    font-size: 32px;
    font-weight: 800;
    color: var(--ink);
    margin: 0;
}

.chapter-select {
    padding: 10px 20px;
    border: 1px solid var(--orange);
    border-radius: 8px;
    font-family: inherit;
    font-size: 14px;
    font-weight: 600;
    color: var(--ink);
    cursor: pointer;
    background: #fff;
    min-width: 180px;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 15px center;
}

.detail-content {
    font-size: 16px;
    line-height: 1.8;
    color: #444;
}

.detail-content p {
    margin-bottom: 24px;
}

.detail-content img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    margin: 20px 0;
}

.detail-content strong {
    color: var(--ink);
}

.detail-content h3 {
    font-size: 24px;
    font-weight: 800;
    margin: 40px 0 20px;
    color: var(--ink);
}

/* Sidebar Styles */
.detail-sidebar {
    position: sticky;
    top: 100px;
}

.sidebar-title {
    font-size: 14px;
    font-weight: 800;
    color: var(--ink);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--orange);
    display: inline-block;
}

.sidebar-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 20px;
}

.sidebar-item {
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px;
    background: #fff;
    border-radius: 10px;
    border: 1px solid #eee;
    transition: all 0.3s ease;
}

.sidebar-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.sidebar-item.active {
    border-color: var(--orange);
    box-shadow: 0 0 0 1px var(--orange);
}

.sidebar-thumb {
    flex: 0 0 50px;
    height: 50px;
    border-radius: 6px;
    background: #f0f4f8;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.sidebar-item h4 {
    font-size: 13px;
    font-weight: 700;
    color: var(--ink);
    line-height: 1.4;
    margin: 0;
}

.sidebar-item.active h4 {
    color: var(--ink); /* Keep text dark in active state as per SS */
}

.sidebar-footer {
    margin-top: 15px;
    font-size: 11px;
    color: #999;
    font-style: italic;
}

/* Navigation Buttons */
.mnemonic-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 60px;
    padding-top: 30px;
    border-top: 1px solid #eee;
    gap: 20px;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    background: #f8f9fa;
    border-radius: 10px;
    text-decoration: none;
    color: var(--ink);
    font-weight: 700;
    transition: all 0.2s ease;
    border: 1px solid transparent;
}

.nav-btn:hover {
    background: var(--white);
    border-color: var(--orange);
    color: var(--orange);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.nav-btn span {
    font-size: 14px;
}

/* ══════════════════════════════════════════
   RESPONSIVE
══════════════════════════════════════════ */
@media (max-width: 1024px) {
    .mnemonics-grid { grid-template-columns: repeat(3, 1fr); }
    .mnemonics-hero h1 { font-size: 42px; }
    .mnemonics-hero .hero-image { display: none; }
    .mnemonic-layout {
        grid-template-columns: 1fr;
        gap: 60px;
    }
}

@media (max-width: 768px) {
    .mnemonics-grid { grid-template-columns: repeat(2, 1fr); }
    .mnemonics-hero { padding: 60px 0; }
    .mnemonics-listing h2 { font-size: 30px; }
}

@media (max-width: 480px) {
    .mnemonics-grid { grid-template-columns: 1fr; }
}