/* ═════════════════════════════════════════════════════════════════════════
   CSS VARIABLES & THEME SETUP
   ═════════════════════════════════════════════════════════════════════════ */
:root {
    /* Typography */
    --font-primary: 'Satoshi', sans-serif;
    --font-mono: 'Space Mono', monospace;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-smooth: 0.45s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    --transition-bounce: 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* DARK THEME (default) */
:root[data-theme="dark"] {
    --bg-primary: #004831;
    --bg-secondary: #182F25;
    --bg-tertiary: rgba(24, 47, 37, 0.5);
    --text-primary: #ffffff;
    --text-secondary: #95B5A9;
    --accent-primary: #20C683;
    --accent-hover: #001f12;
    --border-subtle: rgba(149, 181, 169, 0.2);
    --border-emphasis: rgba(149, 181, 169, 0.4);
    --shadow-sm: none;
    --shadow-md: none;
    --shadow-lg: none;
    --bg-pill: rgba(24, 47, 37, 0.8);
}

/* LIGHT THEME */
:root[data-theme="light"] {
    --bg-primary: #f0efed;
    --bg-secondary: #ffffff;
    --bg-tertiary: rgba(255, 255, 255, 0.8);
    --text-primary: #12211a;
    --text-secondary: #004831;
    --accent-primary: #20C683;
    --accent-hover: #001f12;
    --border-subtle: rgba(18, 33, 26, 0.1);
    --border-emphasis: rgba(18, 33, 26, 0.2);
    --shadow-sm: none;
    --shadow-md: none;
    --shadow-lg: none;
    --bg-pill: rgba(18, 33, 26, 0.05);
}

/* ═════════════════════════════════════════════════════════════════════════
   GLOBAL RESET & BASE STYLES
   ═════════════════════════════════════════════════════════════════════════ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

.mono { font-family: var(--font-mono); letter-spacing: 0.05em; }
.accent-text { color: var(--accent-primary); }
.hidden { display: none !important; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

.app-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ═════════════════════════════════════════════════════════════════════════
   HEADER
   ═════════════════════════════════════════════════════════════════════════ */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 20px;
    margin-bottom: 16px;
    flex-shrink: 0;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 1.1rem;
    text-decoration: none;
    color: inherit;
    opacity: 0.85;
    transition: opacity 0.2s ease;
}
.brand:hover { opacity: 1; }
.brand-icon { color: #306E56; }

.controls { display: flex; gap: 16px; }
.icon-btn {
    color: var(--text-secondary);
    padding: 8px;
    border-radius: 50%;
    transition: color var(--transition-fast), background-color var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    width: 40px;
    height: 40px;
}
.icon-btn:hover { color: var(--accent-primary); background-color: var(--bg-tertiary); }

/* Theme Icon Animation */
#theme-toggle .feather { position: absolute; transition: transform 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55), opacity var(--transition-base); }
:root[data-theme="dark"] .theme-icon-moon { opacity: 1; transform: rotate(0deg); }
:root[data-theme="dark"] .theme-icon-sun { opacity: 0; transform: rotate(90deg); }
:root[data-theme="light"] .theme-icon-moon { opacity: 0; transform: rotate(-90deg); }
:root[data-theme="light"] .theme-icon-sun { opacity: 1; transform: rotate(0deg); }

.lang-text { font-weight: 600; font-size: 0.9rem; }

/* ═════════════════════════════════════════════════════════════════════════
   MAIN CONTENT & HERO
   ═════════════════════════════════════════════════════════════════════════ */
.main-content { flex: 1; display: flex; flex-direction: column; min-height: 0; }

/* ═════════════════════════════════════════════════════════════════════════
   SCREEN SYSTEM
   ═════════════════════════════════════════════════════════════════════════ */
.screen { display: none; flex: 1; flex-direction: column; min-height: 0; }
.screen.active {
    display: flex;
    animation: screenEnter 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
}
@keyframes screenEnter {
    from { opacity: 0; transform: translateY(16px); filter: blur(3px); }
    to   { opacity: 1; transform: translateY(0);    filter: blur(0px); }
}

/* Screen 1 inherits hero + upload-section layout */
#screen-drop { gap: 16px; }

/* Staggered entrance animation */
.anim-item {
    opacity: 0;
    transform: translateY(24px);
    animation: itemSlideUp 0.65s cubic-bezier(0.16, 1, 0.3, 1) var(--delay, 0s) both;
}
@keyframes itemSlideUp {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}


.hero {
    text-align: center;
    flex-shrink: 0;
    padding: 4px 20px 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}
.title {
    font-size: clamp(2.2rem, 6vw, 3.8rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
}
.hero-brand {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    color: var(--text-secondary);
}
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: rgba(32, 198, 131, 0.08);
    border: 1px solid rgba(32, 198, 131, 0.22);
    border-radius: 999px;
    font-size: 10.5px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--accent-primary);
}
.badge-star {
    width: 11px;
    height: 11px;
    fill: currentColor;
    flex-shrink: 0;
}

/* ── Screen 2: File loaded ── */
.file-screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 32px;
    padding: 32px 20px;
    text-align: center;
}
.file-screen-top { display: flex; flex-direction: column; align-items: center; gap: 14px; }
.file-type-badge {
    font-size: 0.7rem;
    letter-spacing: 0.16em;
    color: var(--accent-primary);
    background: rgba(32, 198, 131, 0.1);
    border: 1px solid rgba(32, 198, 131, 0.28);
    border-radius: 6px;
    padding: 5px 13px;
    text-transform: uppercase;
}
.file-screen-name {
    font-size: clamp(1.4rem, 4vw, 2.2rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    max-width: 640px;
    word-break: break-all;
    line-height: 1.15;
}
.file-screen-size { color: var(--text-secondary); font-size: 1rem; }
.file-screen-controls { width: 100%; max-width: 480px; }
.file-screen-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    width: 100%;
    max-width: 380px;
}
.btn-huge {
    width: 100%;
    padding: 19px 40px;
    font-size: 1.1rem;
    border-radius: 999px;
    margin-top: 0;
}
.btn-ghost {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    border-radius: 999px;
    transition: color var(--transition-fast), background-color var(--transition-fast);
}
.btn-ghost:hover { color: var(--text-primary); background-color: rgba(255,255,255,0.06); }
.btn-ghost .feather { width: 15px; height: 15px; }

/* ── Screen 3: Compressing animation ── */
#screen-compressing { position: relative; }
.compressing-ui {
    position: relative;
    z-index: 2;
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 20px;
}
.anim-logo-wrap { position: relative; display: flex; align-items: center; justify-content: center; }
.anim-logo {
    color: #306E56;
    display: block;
    animation: logoPulse 2.6s ease-in-out infinite;
}
@keyframes logoPulse {
    0%, 100% { transform: scale(1);    filter: brightness(1);   opacity: 0.92; }
    50%       { transform: scale(1.1); filter: brightness(1.25); opacity: 1;    }
}
.anim-status {
    font-size: 0.9rem;
    color: var(--text-secondary);
    letter-spacing: 0.03em;
    transition: opacity 0.15s ease;
}
.anim-percent {
    font-size: 4rem;
    font-weight: 700;
    color: var(--accent-primary);
    letter-spacing: -0.05em;
    line-height: 1;
}

/* ── Screen 4: Results ── */
.results-screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
    padding: 32px 20px;
    text-align: center;
}
.results-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    width: 100%;
    max-width: 380px;
}

/* ═════════════════════════════════════════════════════════════════════════
   FILE TYPE SELECTOR (Sliding Pill)
   ═════════════════════════════════════════════════════════════════════════ */
.selector-container { display: flex; justify-content: center; }
.file-type-selector {
    position: relative;
    display: flex;
    background-color: var(--bg-pill);
    border-radius: 999px;
    padding: 4px;
    width: 240px;
    box-shadow: inset 0 1px 4px rgba(0,0,0,0.05);
}
.selector-btn {
    flex: 1;
    position: relative;
    z-index: 2;
    padding: 10px;
    font-weight: 600;
    color: var(--text-secondary);
    transition: color var(--transition-smooth);
    text-align: center;
}
.selector-btn.active { color: var(--bg-secondary); }
/* Light theme text adjustment for contrast on active pill */
:root[data-theme="light"] .selector-btn.active { color: #fff; }

.selector-pill {
    position: absolute;
    top: 4px;
    left: 4px;
    width: calc(50% - 4px);
    height: calc(100% - 8px);
    background-color: var(--accent-primary);
    border-radius: 999px;
    z-index: 1;
    transition: transform var(--transition-smooth);
    box-shadow: var(--shadow-sm);
}
/* State managed by JS applying styles to .selector-pill */

/* ═════════════════════════════════════════════════════════════════════════
   DROPZONE
   ═════════════════════════════════════════════════════════════════════════ */
.upload-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.dropzone {
    background-color: transparent;
    border: 2px dashed var(--border-emphasis);
    border-radius: 20px;
    padding: 60px 40px;
    text-align: center;
    transition: border-color 0.25s ease, background-color 0.25s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    flex: 1;
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.dropzone:hover {
    border-color: var(--accent-primary);
}
.dropzone.dragging {
    border-color: var(--accent-primary);
    background-color: rgba(32, 198, 131, 0.05);
}

.empty-state { color: var(--text-secondary); transition: opacity var(--transition-fast); }
.upload-icon { width: 64px; height: 64px; margin-bottom: 20px; color: var(--accent-primary); opacity: 0.75; }
.drop-text { font-size: 1.2rem; font-weight: 500; color: var(--text-primary); }
.sub-text { display: block; font-size: 0.9rem; margin-top: 8px; color: var(--text-secondary); }
.drop-formats {
    display: inline-block;
    margin-top: 20px;
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    background-color: var(--bg-primary);
    border: 1px solid var(--border-subtle);
    border-radius: 20px;
    padding: 4px 14px;
    opacity: 0.7;
}

/* File Card */
.file-card {
    background-color: var(--bg-primary);
    border-radius: 16px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    width: 100%;
    max-width: 500px;
    box-shadow: var(--shadow-sm);
    animation: slideUpBounce 0.5s var(--transition-spring) forwards;
}
.file-icon { color: var(--accent-primary); width: 32px; height: 32px; }
.file-info { flex: 1; text-align: left; }
.file-name { display: block; font-weight: 600; margin-bottom: 4px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file-size { font-size: 0.85rem; color: var(--text-secondary); }
.remove-file-btn { padding: 8px; color: var(--text-secondary); border-radius: 50%; }
.remove-file-btn:hover { background-color: var(--bg-tertiary); color: var(--text-primary); }

/* ═════════════════════════════════════════════════════════════════════════
   CONTROLS SECTION
   ═════════════════════════════════════════════════════════════════════════ */
.controls-section {
    background-color: var(--bg-secondary);
    padding: 30px;
    border-radius: 20px;
    border: 1px solid var(--border-subtle);
}

.mode-controls { animation: fadeIn 0.3s ease forwards; }

.control-header { display: flex; justify-content: space-between; margin-bottom: 20px; font-weight: 500; }
.slider-labels { display: flex; justify-content: space-between; font-size: 0.75rem; color: var(--text-secondary); margin-top: 12px; }

/* Custom Slider (Material Style) */
input[type=range] {
    -webkit-appearance: none;
    width: 100%;
    height: 4px;
    background: var(--border-emphasis);
    border-radius: 4px;
    outline: none;
    transition: background var(--transition-fast);
}
/* Webkit Thumb */
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: var(--bg-primary);
    border: 3px solid var(--accent-primary);
    border-radius: 50%;
    cursor: pointer;
    transition: transform var(--transition-fast);
}
input[type=range]::-webkit-slider-thumb:hover { transform: scale(1.15); }
input[type=range]:active::-webkit-slider-thumb { transform: scale(0.95); }
/* Firefox Thumb */
input[type=range]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--bg-primary);
    border: 3px solid var(--accent-primary);
    border-radius: 50%;
    cursor: pointer;
    transition: transform var(--transition-fast);
    box-sizing: border-box;
}
input[type=range]::-moz-range-thumb:hover { transform: scale(1.15); }
input[type=range]:active::-moz-range-thumb { transform: scale(0.95); }

/* PDF Controls Styles */
.control-group { margin-bottom: 24px; }
.group-label { display: block; margin-bottom: 12px; font-weight: 500; font-size: 0.95rem; }
.radio-pills { display: flex; gap: 10px; flex-wrap: wrap; }
.radio-pill { position: relative; }
.radio-pill input { position: absolute; opacity: 0; cursor: pointer; }
.radio-pill span {
    display: inline-block;
    padding: 10px 16px;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-subtle);
    border-radius: 99px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
    cursor: pointer;
}
.radio-pill input:checked ~ span {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    border-color: var(--accent-primary);
}
/* Light theme text contrast fix for active pills */
:root[data-theme="light"] .radio-pill input:checked ~ span { color: #fff; }

.checkbox-group { display: flex; flex-direction: column; gap: 12px; }
.checkbox-label { display: flex; align-items: center; gap: 10px; font-size: 0.95rem; cursor: pointer; }
.checkbox-label input {
    accent-color: var(--accent-primary);
    width: 18px;
    height: 18px;
    cursor: pointer;
}

/* Primary Button */
.btn-primary {
    width: 100%;
    background-color: var(--accent-primary);
    color: #ffffff;
    padding: 16px;
    border-radius: 999px;
    font-weight: 700;
    font-size: 1.05rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 0;
    transition: background-color var(--transition-fast), transform var(--transition-fast);
    position: relative;
    overflow: hidden;
}
.btn-primary:hover:not(:disabled) { transform: translateY(-1px); background-color: #001f12; }
.btn-primary:active:not(:disabled) { transform: translateY(0) scale(0.98); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-icon { width: 20px; height: 20px; }

/* Ripple Effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    transform: scale(0);
    animation: ripple 0.6s linear;
    background-color: rgba(255, 255, 255, 0.3);
}

/* ═════════════════════════════════════════════════════════════════════════
   PROGRESS & RESULTS
   ═════════════════════════════════════════════════════════════════════════ */
.progress-section { margin-top: 20px; }
.progress-header { display: flex; justify-content: space-between; margin-bottom: 10px; font-size: 0.9rem; font-weight: 500; }
.progress-track { height: 10px; background-color: var(--bg-secondary); border-radius: 99px; overflow: hidden; border: 1px solid var(--border-subtle); }
.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-hover));
    border-radius: 99px;
    transition: width 0.3s linear;
}

.working-loader { margin-top: 16px; text-align: center; }
.indeterminate-bar {
    height: 4px;
    background-color: var(--border-subtle);
    border-radius: 99px;
    position: relative;
    overflow: hidden;
    margin-bottom: 8px;
}
.indeterminate-bar::after {
    content: '';
    position: absolute;
    top: 0; left: 0; bottom: 0;
    width: 40%;
    background-color: var(--accent-primary);
    border-radius: 99px;
    animation: indeterminate 1.5s infinite ease-in-out;
}
.working-text { font-size: 0.85rem; color: var(--text-secondary); height: 1.2em; }

/* Results */
.results-section { text-align: center; animation: slideUp 0.5s var(--transition-smooth) forwards; }
.success-header { margin-bottom: 30px; }
.success-icon-container {
    width: 80px; height: 80px;
    background-color: var(--bg-secondary);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    margin: 0 auto 16px;
    border: 3px solid var(--accent-primary);
    color: var(--accent-primary);
}
.success-icon { width: 40px; height: 40px; }

.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-bottom: 30px; }
.stat-card { background-color: var(--bg-secondary); padding: 20px 16px; border-radius: 16px; border: 1px solid var(--border-subtle); }
.stat-card.highlight { background-color: var(--bg-tertiary); border-color: var(--accent-primary); }
.stat-label { display: block; font-size: 0.8rem; color: var(--text-secondary); margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.05em; }
.stat-value { display: block; font-size: 1.2rem; font-weight: 700; }

/* Canvas for confetti */
#confetti-canvas { position: fixed; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; z-index: 999; }

/* ═════════════════════════════════════════════════════════════════════════
   ANIMATIONS
   ═════════════════════════════════════════════════════════════════════════ */
@keyframes ripple { to { transform: scale(4); opacity: 0; } }
@keyframes spin { to { transform: rotate(360deg); } }
.spin { animation: spin 1s linear infinite; }
@keyframes indeterminate {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(350%); }
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes slideUpBounce {
    from { opacity: 0; transform: translateY(50px) scale(0.9); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes bounceIn {
    0% { transform: scale(0); }
    60% { transform: scale(1.1); }
    100% { transform: scale(1); }
}
.bounce-in { animation: bounceIn 0.6s var(--transition-bounce) forwards; }

/* Staggered entrance animations */
.fade-in { animation: fadeIn 0.6s ease forwards; opacity: 0; }
.fade-in-delayed-1 { animation: fadeIn 0.6s ease 0.1s forwards; opacity: 0; }
.fade-in-delayed-2 { animation: fadeIn 0.6s ease 0.2s forwards; opacity: 0; }
.fade-in-delayed-3 { animation: fadeIn 0.6s ease 0.3s forwards; opacity: 0; }

.staggered-1 { animation: slideUp 0.5s ease 0.1s forwards; opacity: 0; transform: translateY(20px); }
.staggered-2 { animation: slideUp 0.5s ease 0.2s forwards; opacity: 0; transform: translateY(20px); }
.staggered-3 { animation: slideUp 0.5s ease 0.3s forwards; opacity: 0; transform: translateY(20px); }
.staggered-4 { animation: slideUp 0.5s ease 0.4s forwards; opacity: 0; transform: translateY(20px); }

/* Text swap Fade */
.fade-text { transition: opacity 0.15s ease; }

/* ═════════════════════════════════════════════════════════════════════════
   SEO CONTENT
   ═════════════════════════════════════════════════════════════════════════ */
.seo-content {
    max-width: 560px;
    margin: 0 auto;
    padding: 20px 20px 0;
    color: var(--text-secondary);
    font-size: 0.8rem;
    line-height: 1.6;
    text-align: center;
    opacity: 0.45;
}

/* ═════════════════════════════════════════════════════════════════════════
   FOOTER
   ═════════════════════════════════════════════════════════════════════════ */
.footer {
    flex-shrink: 0;
    text-align: center;
    padding: 28px 20px 16px;
    color: var(--text-secondary);
    font-size: 0.83rem;
}
.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
    opacity: 0.7;
}
.footer-heart {
    width: 13px;
    height: 13px;
    color: var(--accent-primary);
    fill: var(--accent-primary);
    flex-shrink: 0;
}
.footer a {
    color: var(--accent-primary);
    text-decoration: none;
}
.footer a:hover { text-decoration: underline; }
.footer-privacy {
    font-size: 0.78rem;
    opacity: 0.5;
    max-width: 460px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ═════════════════════════════════════════════════════════════════════════
   MEDIA QUERIES (Mobile First adjustments)
   ═════════════════════════════════════════════════════════════════════════ */
@media (max-width: 768px) {
    .app-container { padding: 16px; }
    .header { margin-bottom: 30px; }
    .title { font-size: 2rem; }
    .dropzone { padding: 40px 20px; min-height: 240px; }
    .upload-icon { width: 52px; height: 52px; }
    .footer { padding: 20px 0 12px; }
    .file-screen { gap: 24px; padding: 24px 16px; }
    .anim-percent { font-size: 3rem; }
    .stats-grid { grid-template-columns: 1fr; gap: 12px; }
    .stat-card { display: flex; justify-content: space-between; align-items: center; }
    .stat-label { margin-bottom: 0; }
    .file-card { flex-direction: column; text-align: center; padding: 24px; }
    .file-info { text-align: center; width: 100%; }
    .radio-pills { flex-direction: column; }
    .radio-pill span { display: block; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
    *, ::before, ::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}