/* ============================================
   Color Palette Studio — Light Theme, Clean UI
   ============================================ */

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

:root {
    --bg: #f9f9fb;
    --bg-card: #ffffff;
    --text: #1a1a2e;
    --text-muted: #6b7280;
    --accent: #e94560;
    --accent-hover: #d63851;
    --border: #e5e7eb;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 6px 20px rgba(0, 0, 0, 0.1);
    --radius: 10px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.app-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 16px;
}

/* Header */
.header {
    text-align: center;
    padding: 28px 0 12px;
}

.header h1 {
    font-size: 1.7rem;
    margin-bottom: 8px;
    color: var(--text);
}

.header p {
    color: var(--text-muted);
    font-size: 0.92rem;
    max-width: 560px;
    margin: 0 auto;
}

/* Sections */
.section {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 22px;
    margin-bottom: 16px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.section h2 {
    font-size: 1rem;
    margin-bottom: 12px;
    font-weight: 600;
    color: var(--text);
}

.section-note {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 14px;
}

/* System Grid */
.system-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.system-btn {
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: 20px;
    background: var(--bg);
    color: var(--text);
    cursor: pointer;
    font-size: 0.82rem;
    transition: all 0.15s ease;
}

.system-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: #fff0f2;
}

.system-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

/* Preset Color Grid */
.preset-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.preset-color {
    aspect-ratio: 1;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    cursor: pointer;
    transition: all 0.15s ease;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-end;
    overflow: hidden;
}

.preset-color:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
    border-color: #ccc;
}

.preset-color.selected {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(233, 69, 96, 0.2), var(--shadow-hover);
}

.preset-color-label {
    font-size: 0.6rem;
    background: rgba(0, 0, 0, 0.5);
    color: #fff;
    width: 100%;
    text-align: center;
    padding: 3px 4px;
    backdrop-filter: blur(4px);
    line-height: 1.2;
}

/* Hover Action Icons */
.preset-color-actions {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    background: rgba(0, 0, 0, 0.35);
    opacity: 0;
    transition: opacity 0.2s ease;
    backdrop-filter: blur(2px);
}

.preset-color:hover .preset-color-actions {
    opacity: 1;
}

.preset-action-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform 0.15s ease, background 0.15s ease;
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.9);
    color: var(--text);
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.preset-action-btn:hover {
    transform: scale(1.15);
    background: #fff;
}

.preset-action-btn.action-fullscreen {
    font-size: 1.1rem;
}

.preset-action-btn.action-advanced {
    font-size: 0.9rem;
}

/* Selected Color */
.selected-display {
    display: flex;
    align-items: center;
    gap: 16px;
}

.selected-swatch {
    width: 72px;
    height: 72px;
    border-radius: var(--radius);
    border: 2px solid var(--border);
    flex-shrink: 0;
    box-shadow: var(--shadow);
}

.selected-name {
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 2px;
}

.selected-hex {
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    color: var(--text-muted);
    font-size: 0.88rem;
}

/* Buttons */
.btn {
    padding: 12px 20px;
    border: none;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s ease;
}

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

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

.btn-secondary {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
}

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

.full-width {
    width: 100%;
    margin-top: 12px;
}

.btn-icon {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
}

.btn-icon:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
}

/* Advanced Section */
.advanced-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.advanced-header h2 {
    margin-bottom: 0;
}

.advanced-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

@media (max-width: 640px) {
    .advanced-layout {
        grid-template-columns: 1fr;
    }
}

/* Gradient Box */
.advanced-visual {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.gradient-box-wrap {
    position: relative;
    width: 100%;
}

.gradient-box-wrap canvas {
    width: 100%;
    aspect-ratio: 1;
    border-radius: var(--radius);
    cursor: crosshair;
    display: block;
    border: 1px solid var(--border);
}

.gradient-cursor {
    position: absolute;
    width: 16px;
    height: 16px;
    border: 2px solid #fff;
    border-radius: 50%;
    box-shadow: 0 0 0 1px rgba(0,0,0,0.3), inset 0 0 2px rgba(0,0,0,0.3);
    pointer-events: none;
    transform: translate(-50%, -50%);
    top: 20%;
    left: 80%;
}

.hue-slider-wrap {
    position: relative;
    width: 100%;
}

.hue-slider-wrap canvas {
    width: 100%;
    height: 20px;
    border-radius: 10px;
    cursor: pointer;
    display: block;
    border: 1px solid var(--border);
}

.hue-cursor {
    position: absolute;
    width: 8px;
    height: 24px;
    background: #fff;
    border: 2px solid #555;
    border-radius: 4px;
    top: 50%;
    left: 5%;
    transform: translate(-50%, -50%);
    pointer-events: none;
    box-shadow: 0 1px 4px rgba(0,0,0,0.3);
}

/* Advanced Inputs */
.advanced-inputs {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.input-row {
    display: grid;
    grid-template-columns: 32px 1fr 56px;
    align-items: center;
    gap: 8px;
}

.input-row.hex-row {
    grid-template-columns: 32px 1fr;
}

.input-row label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
}

.input-row input[type="range"] {
    width: 100%;
    height: 5px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border);
    border-radius: 3px;
    cursor: pointer;
}

.input-row input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.input-row input[type="text"],
.input-row input[type="number"] {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 7px 8px;
    color: var(--text);
    font-size: 0.82rem;
    text-align: center;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
}

.input-row input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(233, 69, 96, 0.1);
}

/* CMYK */
.cmyk-row {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 4px;
}

.cmyk-row label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    width: 36px;
}

.cmyk-inputs {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    flex: 1;
}

.cmyk-inputs input {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 7px 4px;
    color: var(--text);
    font-size: 0.78rem;
    text-align: center;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    width: 100%;
}

.cmyk-inputs input:focus {
    outline: none;
    border-color: var(--accent);
}

/* Fullscreen Overlay */
.fullscreen-overlay {
    position: fixed;
    inset: 0;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.3s ease;
}

.fullscreen-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.fullscreen-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.35);
    color: #fff;
    border: 2px solid rgba(255,255,255,0.4);
    font-size: 1.4rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    z-index: 10001;
    backdrop-filter: blur(4px);
}

.fullscreen-close:hover {
    background: rgba(0, 0, 0, 0.6);
    border-color: #fff;
    transform: scale(1.1);
}

.fullscreen-info {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.45);
    padding: 10px 24px;
    border-radius: 30px;
    color: #fff;
    font-size: 0.95rem;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    backdrop-filter: blur(10px);
    white-space: nowrap;
}

/* Ad Slots */
.ad-slot {
    max-width: 800px;
    margin: 0 auto 16px;
    padding: 0 16px;
}

.ad-slot-top {
    margin-top: 8px;
}

.ad-slot-bottom {
    margin-bottom: 8px;
}

.ad-placeholder {
    background: #f3f4f6;
    border: 1px dashed #d1d5db;
    border-radius: var(--radius);
    padding: 20px;
    text-align: center;
    color: #9ca3af;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.ad-slot-top .ad-placeholder {
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ad-slot-inline .ad-placeholder,
.ad-slot-mid .ad-placeholder {
    min-height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ad-slot-bottom .ad-placeholder {
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* SEO Content */
.seo-content {
    color: var(--text-muted);
    font-size: 0.88rem;
}

.seo-content h2 {
    color: var(--text);
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.seo-content h3 {
    color: var(--text);
    font-size: 0.95rem;
    margin: 14px 0 6px;
}

.seo-content p {
    margin-bottom: 10px;
    line-height: 1.7;
}

.seo-content ul {
    padding-left: 20px;
    margin-bottom: 10px;
}

.seo-content li {
    margin-bottom: 6px;
    line-height: 1.6;
}

/* Footer */
.footer {
    text-align: center;
    padding: 24px 16px;
    color: var(--text-muted);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
    max-width: 800px;
    margin: 0 auto;
}

/* Responsive */
@media (max-width: 480px) {
    .app-container {
        padding: 12px;
    }

    .preset-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 8px;
    }

    .preset-action-btn {
        width: 30px;
        height: 30px;
        font-size: 0.85rem;
    }

    .fullscreen-close {
        top: 12px;
        right: 12px;
        width: 44px;
        height: 44px;
    }
}

/* Touch devices: show actions on tap */
@media (hover: none) {
    .preset-color-actions {
        opacity: 0;
    }
    .preset-color:active .preset-color-actions {
        opacity: 1;
    }
}