/* ═══════════════════════════════════════════════════════
   🔐 隐写加密通讯 — Apple 风 · 毛玻璃 · 极致精致
   ═══════════════════════════════════════════════════════ */

:root {
    /* ── 浅色（默认） ── */
    --bg: #f5f5f7;
    --bg-glass: rgba(255,255,255,0.72);
    --bg-glass-strong: rgba(255,255,255,0.88);
    --text: #1d1d1f;
    --text-secondary: #6e6e73;
    --border: rgba(0,0,0,0.08);
    --border-strong: rgba(0,0,0,0.14);
    --primary: #0071e3;
    --primary-dark: #0058b0;
    --primary-light: rgba(0,113,227,0.08);
    --success: #34c759;
    --success-dark: #248a3d;
    --danger: #ff3b30;
    --danger-light: rgba(255,59,48,0.08);
    --warning: #ff9500;
    --warning-light: rgba(255,149,0,0.10);
    --radius: 18px;
    --radius-sm: 12px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow: 0 8px 24px rgba(0,0,0,0.06), 0 2px 6px rgba(0,0,0,0.04);
    --shadow-md: 0 12px 32px rgba(0,0,0,0.08);
    --shadow-lg: 0 20px 48px rgba(0,0,0,0.12), 0 6px 16px rgba(0,0,0,0.06);
    --backdrop: saturate(180%) blur(24px);
    --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    --font-mono: "SF Mono", "Fira Code", ui-monospace, Menlo, Consolas, monospace;
}

/* ── 深色模式 ── */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1c1c1e;
        --bg-glass: rgba(44,44,48,0.72);
        --bg-glass-strong: rgba(54,54,58,0.88);
        --text: #f5f5f7;
        --text-secondary: #a1a1a6;
        --border: rgba(255,255,255,0.10);
        --border-strong: rgba(255,255,255,0.18);
        --primary: #0a84ff;
        --primary-dark: #409cff;
        --primary-light: rgba(10,132,255,0.14);
        --success: #30d158;
        --danger: #ff453a;
        --danger-light: rgba(255,69,58,0.14);
        --warning: #ff9f0a;
        --warning-light: rgba(255,159,10,0.14);
        --shadow: 0 8px 24px rgba(0,0,0,0.35), 0 2px 6px rgba(0,0,0,0.22);
        --shadow-md: 0 12px 32px rgba(0,0,0,0.40);
        --shadow-lg: 0 20px 48px rgba(0,0,0,0.48), 0 6px 16px rgba(0,0,0,0.30);
    }
}

* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html { scroll-behavior: smooth; }

body {
    font-family: var(--font);
    background: var(--bg);
    /* Apple 式柔和双色光晕 */
    background-image:
        radial-gradient(ellipse 80% 50% at 50% -10%, rgba(0,113,227,0.10), transparent 60%),
        radial-gradient(ellipse 60% 40% at 90% 110%, rgba(52,199,89,0.06), transparent 60%),
        radial-gradient(ellipse 50% 35% at 10% 90%, rgba(10,132,255,0.04), transparent 60%);
    background-attachment: fixed;
    color: var(--text);
    line-height: 1.55;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

.container { max-width: 580px; margin: 0 auto; padding: 32px 16px 56px; }

/* ═══════ 顶部 Header ═══════ */
header { text-align: center; margin-bottom: 32px; }
header .logo {
    width: 56px; height: 56px; margin: 0 auto 14px;
    background: linear-gradient(135deg, var(--primary), #5ac8fa);
    border-radius: 16px;
    display: flex; align-items: center; justify-content: center;
    font-size: 28px; color: #fff;
    box-shadow: 0 8px 24px rgba(0,113,227,0.35), inset 0 1px 0 rgba(255,255,255,0.25);
    transform: translateZ(0); /* 启用 GPU 合成 */
}
header h1 {
    font-size: 1.6rem; font-weight: 700; letter-spacing: -0.025em;
    background: linear-gradient(135deg, var(--text) 30%, var(--text-secondary));
    -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
header .subtitle { color: var(--text-secondary); font-size: 0.88rem; margin-top: 4px; font-weight: 400; }

/* ═══════ Tab 切换（分段控件风格） ═══════ */
.tabs {
    display: flex; gap: 3px; margin-bottom: 22px; padding: 3px;
    background: var(--bg-glass); backdrop-filter: var(--backdrop); -webkit-backdrop-filter: var(--backdrop);
    border: 1px solid var(--border); border-radius: 14px;
    box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255,255,255,0.5);
}
.tab-btn {
    flex: 1; padding: 10px 14px; border: none; background: transparent;
    border-radius: 11px; font-size: 0.95rem; font-weight: 600; color: var(--text-secondary);
    cursor: pointer; transition: all .25s cubic-bezier(.4,0,.2,1); font-family: inherit;
}
.tab-btn:hover { color: var(--text); background: rgba(0,0,0,0.03); }
.tab-btn.active {
    background: var(--bg-glass-strong); color: var(--text);
    box-shadow: 0 2px 8px rgba(0,0,0,0.08), inset 0 1px 0 rgba(255,255,255,0.6);
}
.tab-content { display: none; }
.tab-content.active { display: block; animation: fadeUp .35s cubic-bezier(.4,0,.2,1); }
@keyframes fadeUp { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* ═══════ 卡片（高级毛玻璃） ═══════ */
.card {
    background: var(--bg-glass); backdrop-filter: var(--backdrop); -webkit-backdrop-filter: var(--backdrop);
    border: 1px solid var(--border); border-radius: var(--radius);
    padding: 20px; margin-bottom: 14px;
    box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255,255,255,0.5);
    transition: box-shadow .3s, border-color .3s, transform .3s;
}
.card:hover { box-shadow: var(--shadow), inset 0 1px 0 rgba(255,255,255,0.5); }
.card label { display: block; font-weight: 600; margin-bottom: 10px; color: var(--text); font-size: 0.92rem; letter-spacing: -0.01em; }

/* ═══════ 输入框 ═══════ */
textarea, input[type="text"] {
    width: 100%; padding: 12px 14px; border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm); font-size: 0.97rem; font-family: inherit;
    resize: vertical; background: var(--bg-glass-strong); color: var(--text);
    transition: border-color .2s, box-shadow .2s; line-height: 1.5;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.03);
}
textarea { min-height: 96px; }
textarea:focus, input[type="text"]:focus {
    outline: none; border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0,113,227,0.15), inset 0 1px 2px rgba(0,0,0,0.03);
}
.char-count { text-align: right; font-size: 0.78rem; color: var(--text-secondary); margin-top: 6px; font-variant-numeric: tabular-nums; }
.hint { color: var(--text-secondary); font-size: 0.78rem; margin-top: 6px; display: block; }

/* ═══════ 密钥模式单选（卡片式） ═══════ */
.radio-group { display: flex; flex-direction: column; gap: 8px; margin-top: 6px; }
.radio-item {
    display: flex; align-items: center; gap: 12px; padding: 13px 14px;
    border: 1px solid var(--border-strong); border-radius: var(--radius-sm);
    cursor: pointer; transition: all .2s; background: var(--bg-glass-strong);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}
.radio-item:hover { border-color: var(--primary); }
.radio-item:has(input:checked) {
    border-color: var(--primary); background: var(--primary-light);
    box-shadow: 0 0 0 1px var(--primary), inset 0 1px 0 rgba(255,255,255,0.4);
}
.radio-item input[type="radio"] {
    accent-color: var(--primary); width: 20px; height: 20px; flex-shrink: 0;
}
.radio-item .radio-label { font-size: 0.93rem; font-weight: 500; }
.radio-item .radio-desc { font-size: 0.76rem; color: var(--text-secondary); margin-top: 2px; }
.key-input-wrapper { margin-top: 10px; }

/* ═══════ 上传区域 ═══════ */
.upload-area {
    position: relative;
    border: 2px dashed var(--border-strong); border-radius: var(--radius-sm);
    padding: 30px 16px; text-align: center; cursor: pointer; transition: all .25s;
    background: var(--bg-glass-strong);
}
.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary); background: var(--primary-light);
}
.carrier-clear {
    position: absolute; top: 8px; right: 8px;
    width: 28px; height: 28px; border-radius: 50%;
    border: none; background: rgba(0,0,0,0.08); color: var(--text-secondary);
    font-size: 1.2rem; line-height: 1; cursor: pointer;
    display: none; align-items: center; justify-content: center;
    transition: all .2s; z-index: 2;
}
.carrier-clear:hover { background: var(--danger); color: #fff; transform: scale(1.1); }
.carrier-clear:active { transform: scale(0.95); }
.btn-remove-carrier {
    margin-left: 8px; padding: 3px 10px; font-size: 0.78rem; font-weight: 600;
    color: var(--danger); background: rgba(255,59,48,0.08);
    border: 1px solid rgba(255,59,48,0.3); border-radius: 6px;
    cursor: pointer; transition: all .2s; vertical-align: middle;
}
.btn-remove-carrier:hover { background: var(--danger); color: #fff; }
.upload-hint { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.8; }
.upload-hint .upload-icon { font-size: 30px; display: block; margin-bottom: 6px; }
.upload-hint small { color: var(--text-secondary); font-size: 0.78rem; opacity: 0.8; }
.upload-info { color: var(--success); font-weight: 600; font-size: 0.9rem; display: flex; align-items: center; gap: 6px; justify-content: center; }

/* ═══════ 按钮（Apple 风） ═══════ */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 6px;
    padding: 12px 24px; border: none; border-radius: var(--radius-sm);
    font-size: 0.97rem; font-weight: 600; cursor: pointer; transition: all .2s;
    text-decoration: none; font-family: inherit; letter-spacing: -0.01em;
}
.btn:active { transform: scale(0.97); }
.btn-primary {
    background: var(--primary); color: #fff;
    box-shadow: 0 4px 12px rgba(0,113,227,0.35), inset 0 1px 0 rgba(255,255,255,0.2);
}
.btn-primary:hover { background: var(--primary-dark); box-shadow: 0 6px 18px rgba(0,113,227,0.40); }
.btn-success {
    background: var(--success); color: #fff;
    box-shadow: 0 4px 12px rgba(52,199,89,0.35), inset 0 1px 0 rgba(255,255,255,0.2);
}
.btn-success:hover { background: var(--success-dark); box-shadow: 0 6px 18px rgba(52,199,89,0.40); }
.btn-copy {
    background: var(--bg-glass-strong); color: var(--text);
    padding: 8px 14px; font-size: 0.85rem; border: 1px solid var(--border-strong);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}
.btn-copy:hover { background: rgba(0,0,0,0.04); }
.btn-block { width: 100%; margin-top: 10px; padding: 14px 24px; font-size: 1rem; }
.btn-secondary { background: var(--bg-glass-strong); color: var(--text); border: 1px solid var(--border-strong); }
.btn-secondary:hover { background: rgba(0,0,0,0.04); }

/* ═══════ 进度条 ═══════ */
.progress-wrap { display: none; margin-top: 14px; }
.progress-wrap.show { display: block; animation: fadeUp .3s ease; }
.progress-track {
    height: 6px; background: var(--border); border-radius: 3px; overflow: hidden;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.06);
}
.progress-fill {
    height: 100%; width: 0%; border-radius: 3px;
    background: linear-gradient(90deg, var(--primary), #5ac8fa);
    transition: width .3s ease; box-shadow: 0 0 8px rgba(0,113,227,0.4);
}
.progress-text {
    display: flex; justify-content: space-between; align-items: center;
    margin-top: 6px; font-size: 0.78rem; color: var(--text-secondary);
}
.progress-text .stage { font-weight: 600; color: var(--primary); }

/* ═══════ 加载态 ═══════ */
.loading { text-align: center; padding: 36px 16px; }
.spinner {
    width: 36px; height: 36px;
    border: 3px solid var(--border-strong); border-top-color: var(--primary);
    border-radius: 50%; animation: spin .7s linear infinite; margin: 0 auto 12px;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading p { color: var(--text-secondary); font-size: 0.9rem; }

/* ═══════ 结果区 ═══════ */
.result-area { margin-top: 20px; animation: fadeUp .35s cubic-bezier(.4,0,.2,1); }

.info-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.info-item {
    background: var(--bg-glass-strong); padding: 10px 12px;
    border-radius: var(--radius-sm); font-size: 0.85rem; border: 1px solid var(--border);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}
.info-item .label { color: var(--text-secondary); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 2px; font-weight: 500; }
.info-item .value { font-weight: 600; color: var(--text); font-variant-numeric: tabular-nums; }

/* ═══════ 密钥展示 ═══════ */
.key-display { display: flex; align-items: center; gap: 10px; }
.key-display code {
    flex: 1; background: var(--bg-glass-strong); padding: 10px 14px;
    border-radius: var(--radius-sm); font-family: var(--font-mono); font-size: 0.88rem;
    word-break: break-all; color: var(--primary-dark); border: 1px solid var(--border);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}

/* ═══════ 预览 ═══════ */
.preview-wrapper {
    background: var(--bg-glass-strong); border-radius: var(--radius-sm);
    padding: 20px; text-align: center; border: 1px solid var(--border);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}
#result-canvas {
    image-rendering: pixelated; image-rendering: crisp-edges;
    width: 100%; max-width: 240px; height: auto; border-radius: 8px; box-shadow: var(--shadow);
}
.result-image {
    image-rendering: pixelated; image-rendering: crisp-edges;
    width: 100%; max-width: 240px; height: auto;
    border-radius: 8px; box-shadow: var(--shadow);
    display: block; margin: 0 auto;
    -webkit-touch-callout: default; touch-action: default;
}
.preview-note { margin-top: 10px; font-size: 0.78rem; color: var(--text-secondary); }

/* ═══════ 原图区域（1:1 不放大） ═══════ */
.original-wrap {
    background: var(--bg-glass-strong); border-radius: var(--radius-sm);
    padding: 14px; text-align: center; border: 1px solid var(--border);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}
.original-wrap .result-image {
    image-rendering: auto;
    width: auto; max-width: 100%;
    height: auto; max-height: 320px;
    border-radius: 8px; box-shadow: var(--shadow);
    display: block; margin: 0 auto;
    -webkit-touch-callout: default; touch-action: default;
}
.original-wrap .result-image:active { opacity: 0.85; }

/* ═══════ 错误区 ═══════ */
.error-area {
    margin-top: 16px; background: var(--danger-light); border: 1px solid rgba(255,59,48,0.25);
    border-radius: var(--radius); padding: 16px; text-align: center; animation: fadeUp .3s ease;
}
.error-icon { font-size: 1.8rem; margin-bottom: 6px; }
.error-area p { color: var(--danger); font-weight: 600; font-size: 0.92rem; }

/* ═══════ 解码文本输出 ═══════ */
.text-output {
    background: var(--bg-glass-strong); border: 1px solid var(--border);
    border-radius: var(--radius-sm); padding: 14px; min-height: 80px; max-height: 300px;
    overflow-y: auto; white-space: pre-wrap; word-break: break-all;
    font-size: 0.92rem; line-height: 1.6; color: var(--text);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.4);
}

/* ═══════ Toast（毛玻璃浮层） ═══════ */
.toast {
    position: fixed; bottom: 40px; left: 50%; transform: translateX(-50%) translateY(20px);
    background: rgba(30,30,30,0.88); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    color: #fff; padding: 12px 24px; border-radius: 12px; font-size: 0.88rem; font-weight: 500;
    opacity: 0; pointer-events: none; transition: all .35s cubic-bezier(.4,0,.2,1);
    z-index: 999; box-shadow: var(--shadow-lg); max-width: 90vw; text-align: center;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.success { background: rgba(52,199,89,0.95); }
.toast.error   { background: rgba(255,59,48,0.95); }

/* ═══════ 容量条 ═══════ */
.capacity-bar { margin-top: 8px; height: 5px; background: var(--border); border-radius: 3px; overflow: hidden; box-shadow: inset 0 1px 2px rgba(0,0,0,0.04); }
.capacity-fill { height: 100%; background: var(--primary); border-radius: 3px; transition: width .3s, background .3s; }

/* ═══════ 微信提示 ═══════ */
.wechat-tip {
    display: none; background: var(--warning-light); border: 1px solid rgba(255,149,0,0.3);
    border-radius: var(--radius); padding: 12px 14px; margin-top: 12px;
    font-size: 0.85rem; color: var(--warning); line-height: 1.6;
}
.wechat-tip.show { display: block; animation: fadeUp .3s ease; }
#hidden-img-for-save { display: none; width: 256px; height: auto; }

/* ═══════ 按钮行 ═══════ */
.btn-row { display: flex; gap: 10px; margin-top: 10px; }
.btn-row .btn { flex: 1; }

/* ═══════ 软上限提示 ═══════ */
.size-warning {
    display: none; background: var(--warning-light); border: 1px solid rgba(255,149,0,0.3);
    border-radius: var(--radius-sm); padding: 10px 14px; margin-top: 10px;
    font-size: 0.82rem; color: var(--warning); line-height: 1.5;
}
.size-warning.show { display: block; animation: fadeUp .3s ease; }
.size-warning strong { font-weight: 700; }

/* ═══════ 模态框（毛玻璃） ═══════ */
.modal-overlay {
    position: fixed; inset: 0; background: rgba(0,0,0,0.40); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
    z-index: 9998; display: flex; align-items: center; justify-content: center;
    opacity: 0; pointer-events: none; transition: opacity .25s;
}
.modal-overlay.show { opacity: 1; pointer-events: auto; }
.modal-box {
    background: var(--bg-glass-strong); backdrop-filter: var(--backdrop); -webkit-backdrop-filter: var(--backdrop);
    border: 1px solid var(--border); border-radius: var(--radius);
    padding: 26px; max-width: 90%; width: 360px; text-align: center;
    box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(255,255,255,0.5);
    transform: scale(0.95); transition: transform .25s cubic-bezier(.4,0,.2,1);
}
.modal-overlay.show .modal-box { transform: scale(1); }
.modal-box h3 { font-size: 1.05rem; margin-bottom: 8px; font-weight: 600; }
.modal-box p { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 16px; line-height: 1.5; }
.modal-box textarea { width: 100%; min-height: 60px; margin-bottom: 14px; font-size: 0.9rem; }
.modal-box .modal-actions { display: flex; gap: 8px; }
.modal-box .modal-actions .btn { flex: 1; padding: 10px; font-size: 0.9rem; }

/* ═══════ iOS Safari 提示 ═══════ */
.ios-tip {
    display: none; margin: 10px 0 6px; padding: 12px 14px;
    background: rgba(0,113,227,0.08); border: 1px solid rgba(0,113,227,0.25);
    border-radius: var(--radius-sm); font-size: 0.85rem; color: var(--text); line-height: 1.6;
}
.ios-tip.show { display: block; animation: fadeUp .3s ease; }
.ios-tip strong { color: var(--primary); }
.ios-longpress-wrap { display: none; text-align: center; margin: 6px 0 14px; }
.ios-longpress-wrap img {
    max-width: 100%; height: auto; border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md); touch-action: default;
    -webkit-touch-callout: default; -webkit-user-select: none; user-select: none;
}
.ios-longpress-wrap img:active { opacity: 0.85; }

/* ═══════ Android / Firefox 提示 ═══════ */
.android-tip {
    display: none; margin: 10px 0 6px; padding: 12px 14px;
    background: rgba(52,199,89,0.08); border: 1px solid rgba(52,199,89,0.25);
    border-radius: var(--radius-sm); font-size: 0.85rem; color: var(--text); line-height: 1.6;
}
.android-tip.show { display: block; animation: fadeUp .3s ease; }
.android-tip strong { color: var(--success-dark); }

/* ═══════ 页面底部 ═══════ */
.page-footer {
    margin-top: 32px; padding: 20px 8px 12px;
    border-top: 1px solid var(--border);
    text-align: center;
}
.footer-inner { max-width: 560px; margin: 0 auto; }
.footer-line {
    font-size: 0.78rem; color: var(--text-secondary);
    line-height: 1.7; margin: 5px 0;
}
.footer-line strong { color: var(--text); font-weight: 600; }
.footer-icon { display: inline-block; margin-right: 2px; }
.footer-divider {
    width: 32px; height: 1px; background: var(--border-strong);
    margin: 12px auto;
}
.footer-brand {
    font-size: 0.72rem; color: var(--text-secondary); opacity: 0.65;
    letter-spacing: 0.02em; display: inline-flex; align-items: center; gap: 6px;
}
.brand-dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), #5ac8fa);
    display: inline-block;
}
.brand-sep { opacity: 0.5; }

/* ═══════ 响应式 ═══════ */
@media (max-width: 480px) {
    .container { padding: 24px 12px 40px; }
    header h1 { font-size: 1.35rem; }
    .info-grid { grid-template-columns: 1fr; }
    .key-display { flex-direction: column; align-items: stretch; }
    .btn-copy { align-self: flex-end; }
    .btn-row { flex-direction: column; }
    .upload-area { padding: 22px 12px; }
    .page-footer { padding: 16px 4px 6px; margin-top: 24px; }
    .footer-line { font-size: 0.74rem; }
}