/* ============================================================
   Uzman Perspektif — 3D Flipbook Viewer Styles (v5 - Pure Diagonal Curl)
   ============================================================ */

:root {
    --bg-primary: #0f0f1a;
    --surface: rgba(255, 255, 255, 0.06);
    --surface-hover: rgba(255, 255, 255, 0.12);
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    --text-primary: #f0f0f5;
    --text-secondary: rgba(240, 240, 245, 0.6);
    --accent: #5b8def;
    --accent-glow: rgba(91, 141, 239, 0.3);
    --page-ratio: 0.7024;
    --toolbar-height: 56px;
    --bottombar-height: 48px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { width: 100%; height: 100%; overflow: hidden; }
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    user-select: none; -webkit-user-select: none;
}

/* ── Loading ─────────────────────────────── */
#loading-screen {
    position: fixed; inset: 0;
    background: var(--bg-primary); z-index: 10000;
    display: flex; align-items: center; justify-content: center;
    transition: opacity 0.5s, visibility 0.5s;
}
#loading-screen.hidden { opacity: 0; visibility: hidden; pointer-events: none; }
.loader-container { text-align: center; }
.book-loader { width: 64px; height: 48px; margin: 0 auto 24px; perspective: 300px; }
.book-loader-inner { position: relative; width: 100%; height: 100%; transform-style: preserve-3d; }
.book-loader-page {
    position: absolute; top: 0; width: 50%; height: 100%;
    background: var(--accent); border-radius: 2px; opacity: 0.8;
}
.book-loader-page.left  { left: 0; transform-origin: right center; animation: ldL 1.4s ease-in-out infinite; }
.book-loader-page.right { right: 0; transform-origin: left center; animation: ldR 1.4s ease-in-out infinite; animation-delay: .7s; }
@keyframes ldL { 0%,100%{ transform: rotateY(0); } 50%{ transform: rotateY(-60deg); } }
@keyframes ldR { 0%,100%{ transform: rotateY(0); } 50%{ transform: rotateY(60deg); } }
.loader-text { font-size: 14px; color: var(--text-secondary); letter-spacing: 1px; }
.dots::after { content: ''; animation: dots 1.5s steps(4,end) infinite; }
@keyframes dots { 0%{content:'';} 25%{content:'.';} 50%{content:'..';} 75%{content:'...';} }

/* ── Toolbar ─────────────────────────────── */
.toolbar {
    position: fixed; top: 0; left: 0; right: 0;
    height: var(--toolbar-height);
    background: var(--surface);
    backdrop-filter: blur(24px) saturate(1.2);
    -webkit-backdrop-filter: blur(24px) saturate(1.2);
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 16px; z-index: 200;
}
.toolbar-left, .toolbar-right { display: flex; align-items: center; gap: 8px; min-width: 0; }
.title { font-size: 15px; font-weight: 600; letter-spacing: .3px; white-space: nowrap; }
@media (max-width: 600px) { .title { display: none; } }
.page-counter { font-size: 13px; font-weight: 500; font-variant-numeric: tabular-nums; color: var(--text-secondary); white-space: nowrap; }

.btn-icon {
    background: transparent; border: none; color: var(--text-primary);
    cursor: pointer; padding: 8px; border-radius: 10px;
    transition: background .2s, transform .15s;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.btn-icon:hover { background: var(--surface-hover); }
.btn-icon:active { transform: scale(0.92); }

/* ── Main Viewer ─────────────────────────── */
#viewer-container {
    position: fixed;
    top: var(--toolbar-height); bottom: var(--bottombar-height);
    left: 0; right: 0;
    display: flex; align-items: center; justify-content: center; overflow: hidden;
    transition: left 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
@media (min-width: 769px) {
    body.sidebar-open #viewer-container {
        left: 280px;
    }
}

.nav-arrow {
    position: absolute; top: 50%; transform: translateY(-50%);
    background: rgba(0,0,0,.4); backdrop-filter: blur(8px);
    border: 1px solid var(--border); color: rgba(255,255,255,.9);
    width: 48px; height: 48px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    cursor: pointer; z-index: 100;
    transition: all .25s; opacity: .7;
}
.nav-arrow:hover { opacity: 1; background: rgba(255,255,255,.15); transform: translateY(-50%) scale(1.08); }
.nav-arrow.prev { left: 16px; }
.nav-arrow.next { right: 16px; }
.nav-arrow:disabled { opacity: .15; cursor: default; pointer-events: none; }
@media (max-width: 768px) { .nav-arrow { display: none; } }

/* ── Book Container ──────────────────────── */
#book-viewport {
    width: 100%; height: 100%;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; touch-action: none;
}
#book-wrapper {
    transform-origin: center center;
    transition: transform .35s cubic-bezier(.25,.46,.45,.94);
    will-change: transform;
}
#book-wrapper.panning { transition: none; }

.book {
    position: relative;
    transform-style: preserve-3d;
    perspective: 2200px;
    background: transparent; /* Transparent so cover sits alone without white background on left */
}

/* ── Leaf (physical sheet) ────────────────── */
.leaf {
    position: absolute; top: 0; left: 50%;
    width: 50%; height: 100%;
    transform-origin: left center;
    transform-style: preserve-3d;
    transition: none;
    cursor: pointer;
}

.leaf-front {
    position: absolute; inset: 0;
    backface-visibility: hidden; -webkit-backface-visibility: hidden;
    background: #fff; overflow: hidden;
    box-shadow: 4px 4px 15px rgba(0,0,0,0.18);
    border-radius: 1px;
}
.leaf-back {
    position: absolute; inset: 0;
    backface-visibility: hidden; -webkit-backface-visibility: hidden;
    background: #fff; overflow: hidden;
    transform: rotateY(180deg);
    box-shadow: -4px 4px 15px rgba(0,0,0,0.18);
    border-radius: 1px;
}

.leaf-front img, .leaf-back img {
    display: block; width: 100%; height: 100%;
    object-fit: cover; pointer-events: none; -webkit-user-drag: none;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: high-quality;
}

/* 100% Symmetrical Independent Crease Shadow (Identical on EVERY spread) */
.leaf-front::after, .leaf-back::after { display: none; }

.leaf.is-top-left .leaf-back::after {
    content: ''; position: absolute; top: 0; right: 0;
    width: 20px; height: 100%; pointer-events: none; z-index: 5;
    display: block !important;
    background: linear-gradient(to left, rgba(0,0,0,.045), transparent);
}
.leaf.is-top-right .leaf-front::after {
    content: ''; position: absolute; top: 0; left: 0;
    width: 20px; height: 100%; pointer-events: none; z-index: 5;
    display: block !important;
    background: linear-gradient(to right, rgba(0,0,0,.045), transparent);
}

/* Central heavy spine gradient (disabled to prevent double darkening) */
.book.is-open::before { display: none !important; }

/* Book shadow on dark workspace */
.book::after {
    content: ''; position: absolute;
    bottom: -16px; left: 2%; width: 96%; height: 26px;
    background: radial-gradient(ellipse at center, rgba(0,0,0,.45) 0%, transparent 75%);
    pointer-events: none; z-index: -1;
}

/* ── Bottom Bar ──────────────────────────── */
.bottom-bar {
    position: fixed; bottom: 0; left: 0; right: 0;
    height: var(--bottombar-height);
    background: var(--surface);
    backdrop-filter: blur(24px) saturate(1.2);
    border-top: 1px solid var(--border);
    display: flex; align-items: center; justify-content: center;
    padding: 0 16px; z-index: 200;
}

.bottom-nav-controls {
    display: flex; align-items: center; justify-content: center; gap: 16px;
}

.bottom-nav-btn {
    width: 36px; height: 36px; border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--border);
    color: var(--text-primary);
    display: flex; align-items: center; justify-content: center;
    cursor: pointer; transition: all 0.2s ease;
}
.bottom-nav-btn:hover:not(:disabled) {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    transform: scale(1.08);
}
.bottom-nav-btn:active:not(:disabled) {
    transform: scale(0.92);
}
.bottom-nav-btn:disabled {
    opacity: 0.25; cursor: default; pointer-events: none;
}

.bottom-page-counter {
    font-size: 14px; font-weight: 600;
    color: var(--text-primary);
    min-width: 90px; text-align: center;
    letter-spacing: 0.5px;
    user-select: none;
}

/* ── Zoom indicator ──────────────────────── */
.zoom-indicator {
    position: fixed; bottom: 70px; left: 50%; transform: translateX(-50%);
    background: rgba(0,0,0,.7); backdrop-filter: blur(10px);
    color: white; padding: 6px 16px; border-radius: 20px;
    font-size: 13px; font-weight: 500;
    opacity: 0; transition: opacity .3s; pointer-events: none; z-index: 300;
}
.zoom-indicator.visible { opacity: 1; }

/* ── Mobile ──────────────────────────────── */
@media (max-width: 768px) {
    :root { --toolbar-height: 50px; --bottombar-height: 44px; }
    .toolbar { padding: 0 10px; }
    .bottom-bar { padding: 0 16px; }
    .toolbar-left, .toolbar-right { gap: 4px; }
    .btn-icon { padding: 6px; }
}
.book.single-page-mode { perspective: none; background: transparent; box-shadow: none; }
.book.single-page-mode::before, .book.single-page-mode::after { display: none; }
.book.single-page-mode .leaf {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    transform-origin: center; transform-style: flat;
    transition: opacity .3s, transform .4s;
    opacity: 0; pointer-events: none; transform: translateX(30px);
}
.book.single-page-mode .leaf.active-single { opacity: 1; pointer-events: auto; transform: translateX(0); z-index: 10 !important; }
.book.single-page-mode .leaf.active-single-prev { opacity: 0; transform: translateX(-30px); }
.book.single-page-mode .leaf-back { display: none; }
.book.single-page-mode .leaf-front { transform: none; }

/* ── High-DPI Crisp Zoom & Sharp Text Rendering ── */
#book-wrapper.is-zoomed {
    will-change: auto !important;
}
#book-wrapper.is-zoomed img {
    image-rendering: -webkit-optimize-contrast;
    image-rendering: high-quality;
}

/* ── Sol Navigasyon Paneli (Sidebar Panel) ── */
.sidebar-overlay { display: none !important; }

.sidebar-drawer {
    position: fixed; top: var(--toolbar-height); left: 0; bottom: 0;
    width: 280px; max-width: 85vw;
    background: rgba(15, 15, 26, 0.95);
    backdrop-filter: blur(20px) saturate(1.4);
    -webkit-backdrop-filter: blur(20px) saturate(1.4);
    border-right: 1px solid var(--border);
    z-index: 150;
    display: flex; flex-direction: column;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 10px 0 25px rgba(0, 0, 0, 0.4);
}
.sidebar-drawer.active { transform: translateX(0); }

.sidebar-header {
    height: var(--toolbar-height);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 16px;
    border-bottom: 1px solid var(--border);
}
.sidebar-title-group {
    display: flex; align-items: center; gap: 10px;
    color: var(--text-primary);
}
.sidebar-title {
    font-size: 16px; font-weight: 600; letter-spacing: 0.3px;
}

.issue-list {
    flex: 1; overflow-y: auto; padding: 16px;
    display: flex; flex-direction: column; gap: 14px;
}
.issue-list::-webkit-scrollbar { width: 6px; }
.issue-list::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.15); border-radius: 3px; }

.issue-card {
    display: flex; gap: 14px; padding: 12px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px; cursor: pointer;
    transition: background 0.2s, border-color 0.2s, transform 0.2s;
    position: relative; overflow: hidden;
}
.issue-card:hover {
    background: var(--surface-hover);
    border-color: var(--border-hover);
    transform: translateY(-2px);
}
.issue-card.active {
    border-color: var(--accent);
    background: rgba(91, 141, 239, 0.12);
    box-shadow: 0 0 15px var(--accent-glow);
}

.issue-cover-wrapper {
    width: 64px; height: 90px;
    border-radius: 6px; overflow: hidden;
    flex-shrink: 0; background: #1a1a2e;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}
.issue-cover {
    width: 100%; height: 100%; object-fit: cover;
    display: block; transition: transform 0.3s;
}
.issue-card:hover .issue-cover { transform: scale(1.05); }

.issue-info {
    display: flex; flex-direction: column; justify-content: center; gap: 4px;
    min-width: 0; flex: 1;
}
.issue-name {
    font-size: 15px; font-weight: 600; color: var(--text-primary);
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.issue-subtitle {
    font-size: 13px; color: var(--text-secondary);
}
.issue-badge {
    display: inline-block; align-self: flex-start;
    padding: 3px 8px; border-radius: 20px;
    font-size: 11px; font-weight: 500;
    background: rgba(255, 255, 255, 0.08); color: var(--text-secondary);
    margin-top: 4px;
}
.issue-card.active .issue-badge {
    background: var(--accent); color: #fff;
}