/* ============================================================
   音轨提取台 · 样式表
   设计方向：深色录音台（Studio Console）
   - 单一强调色（琥珀）仅用于交互元素与进度反馈
   - 等宽字体承担所有数值读数
   - 波形作为与产品行为绑定的动态元素
   ============================================================ */

:root {
    /* 中性色：带极轻微暖调，避免纯灰 */
    --ink-900: #0b0c0e;
    --ink-850: #101216;
    --ink-800: #14161a;
    --ink-750: #191c21;
    --ink-700: #1f232a;
    --line:    #262a32;
    --line-soft: #1e222a;

    --text:      #ecebe7;
    --text-dim:  #9aa0ab;
    --text-faint:#6b7280;

    /* 信号色 */
    --accent:      #f0a02c;
    --accent-deep: #c9811c;
    --accent-wash: rgba(240, 160, 44, 0.12);
    --ok:          #5cb87f;
    --err:         #e5645a;
    --err-wash:    rgba(229, 100, 90, 0.12);

    /* 尺度 */
    --r-sm: 6px;
    --r-md: 10px;
    --r-lg: 14px;
    --r-xl: 20px;

    --sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
            "Microsoft YaHei", "Source Han Sans SC", sans-serif;
    --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

    --shadow: 0 18px 48px -24px rgba(0, 0, 0, 0.9);
    --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

html {
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--ink-900);
    color: var(--text);
    font-family: var(--sans);
    font-size: 16px;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

body::before {
    content: "";
    position: fixed;
    inset: 0 0 auto 0;
    height: 520px;
    background:
        radial-gradient(760px 320px at 50% -140px, rgba(240, 160, 44, 0.09), transparent 72%),
        radial-gradient(520px 260px at 88% -60px, rgba(240, 160, 44, 0.045), transparent 70%);
    pointer-events: none;
    z-index: 0;
}

.topline {
    position: relative;
    z-index: 2;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent) 22%, var(--accent) 78%, transparent);
    opacity: 0.85;
}

.wrap {
    width: 100%;
    max-width: 940px;
    margin: 0 auto;
    padding: 0 24px;
    position: relative;
    z-index: 1;
}

a {
    color: inherit;
}

/* ------------------------------------------------------------
   顶栏
   ------------------------------------------------------------ */

.site-head {
    position: relative;
    z-index: 2;
    padding: 22px 0;
}

.site-head__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text);
}

.brand__mark {
    display: grid;
    place-items: center;
    width: 34px;
    height: 34px;
    border-radius: 9px;
    border: 1px solid var(--line);
    background: var(--ink-800);
    color: var(--accent);
}

.brand__name {
    font-size: 15px;
    font-weight: 620;
    letter-spacing: 0.01em;
}

.site-head__nav {
    display: flex;
    align-items: center;
    gap: 26px;
    font-size: 14px;
    color: var(--text-dim);
}

.site-head__nav a {
    text-decoration: none;
    transition: color 0.18s var(--ease);
}

.site-head__nav a:hover {
    color: var(--text);
}

.site-head__admin {
    padding: 7px 14px;
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--text-dim);
}

.site-head__admin:hover {
    border-color: var(--accent);
    color: var(--accent) !important;
}

/* ------------------------------------------------------------
   主视觉
   ------------------------------------------------------------ */

.hero {
    padding: 46px 0 34px;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    margin: 0 0 22px;
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.16em;
}

.eyebrow__tag {
    padding: 4px 9px;
    border: 1px solid var(--line);
    border-radius: 5px;
    color: var(--text-dim);
    background: var(--ink-850);
}

.eyebrow__arrow {
    color: var(--accent);
    font-size: 13px;
}

.hero__title {
    margin: 0 0 18px;
    font-size: clamp(30px, 5.6vw, 50px);
    line-height: 1.16;
    font-weight: 640;
    letter-spacing: -0.028em;
    max-width: 20ch;
}

.hero__lede {
    margin: 0;
    max-width: 56ch;
    color: var(--text-dim);
    font-size: 16px;
    line-height: 1.78;
}

/* ------------------------------------------------------------
   提示条
   ------------------------------------------------------------ */

.notice {
    margin: 0 0 22px;
    padding: 14px 18px;
    border-radius: var(--r-md);
    font-size: 14px;
    line-height: 1.7;
    border: 1px solid var(--line);
    background: var(--ink-850);
    color: var(--text-dim);
}

.notice strong {
    color: var(--text);
    font-weight: 600;
}

.notice--warn {
    border-color: rgba(229, 100, 90, 0.35);
    background: var(--err-wash);
    color: #f0b8b3;
}

.notice--warn strong {
    color: #ffd9d5;
}

/* ------------------------------------------------------------
   转换台
   ------------------------------------------------------------ */

.tool {
    position: relative;
    border: 1px solid var(--line);
    border-radius: var(--r-xl);
    background: linear-gradient(180deg, var(--ink-800), var(--ink-850));
    box-shadow: var(--shadow);
    overflow: hidden;
}

.tool__head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    padding: 18px 24px;
    border-bottom: 1px solid var(--line-soft);
}

.tool__title {
    margin: 0;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    font-family: var(--mono);
    color: var(--text-dim);
}

.tool__limit {
    margin: 0;
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-faint);
}

.tool__limit b {
    color: var(--text-dim);
    font-weight: 600;
}

.tool__sep {
    margin: 0 6px;
    opacity: 0.5;
}

.panel {
    display: none;
    padding: 26px 24px 28px;
}

.tool[data-state="idle"]  .panel[data-panel="idle"],
.tool[data-state="run"]   .panel[data-panel="run"],
.tool[data-state="done"]  .panel[data-panel="done"],
.tool[data-state="error"] .panel[data-panel="error"] {
    display: block;
    animation: panel-in 0.34s var(--ease) both;
}

@keyframes panel-in {
    from { opacity: 0; transform: translateY(6px); }
    to   { opacity: 1; transform: none; }
}

.panel__actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 22px;
}

/* --- 拖放区 --- */

.drop {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 52px 24px;
    border: 1.5px dashed #2f343d;
    border-radius: var(--r-lg);
    background: var(--ink-900);
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s var(--ease), background 0.2s var(--ease), transform 0.2s var(--ease);
}

.drop:hover {
    border-color: #414852;
    background: var(--ink-850);
}

.drop:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
}

.drop.is-over {
    border-color: var(--accent);
    background: var(--accent-wash);
}

.drop__icon {
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    margin-bottom: 4px;
    border-radius: 12px;
    border: 1px solid var(--line);
    background: var(--ink-800);
    color: var(--text-dim);
    transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.drop:hover .drop__icon,
.drop.is-over .drop__icon {
    color: var(--accent);
    border-color: rgba(240, 160, 44, 0.4);
}

.drop__title {
    font-size: 16px;
    font-weight: 560;
    color: var(--text);
}

.drop__hint {
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-faint);
    letter-spacing: 0.02em;
}

/* --- 文件行 --- */

.fileline {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 20px;
}

.fileline__name {
    font-size: 15px;
    font-weight: 560;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    min-width: 0;
}

.fileline__meta {
    flex: none;
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-faint);
}

/* --- 波形 --- */

.wave {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2px;
    height: 72px;
    padding: 0 2px;
    margin-bottom: 22px;
}

.wave__bar {
    flex: 1 1 auto;
    min-width: 1px;
    border-radius: 1px;
    background: #2b3038;
    transform-origin: center;
    transition: background-color 0.3s var(--ease), transform 0.3s var(--ease);
}

.wave__bar.is-on {
    background: var(--accent);
}

.wave__bar.is-head {
    box-shadow: 0 0 10px rgba(240, 160, 44, 0.75);
}

/* 上传阶段用中性亮色填充，转码阶段切换为信号色，用颜色区分阶段 */
.wave.is-upload .wave__bar.is-on {
    background: #767d8a;
}

.wave.is-upload .wave__bar.is-head {
    box-shadow: 0 0 10px rgba(154, 160, 171, 0.55);
}

.wave.is-live .wave__bar.is-on {
    animation: wave-breathe 1.5s var(--ease) infinite;
}

@keyframes wave-breathe {
    0%, 100% { opacity: 1; }
    50%      { opacity: 0.68; }
}

/* --- 阶段进度 --- */

.phases {
    display: grid;
    gap: 12px;
}

.phase {
    display: grid;
    grid-template-columns: 42px 1fr 44px;
    align-items: center;
    gap: 12px;
    opacity: 0.45;
    transition: opacity 0.25s var(--ease);
}

.phase.is-active,
.phase.is-done {
    opacity: 1;
}

.phase__name {
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.1em;
    color: var(--text-dim);
}

.phase__track {
    position: relative;
    height: 3px;
    border-radius: 999px;
    background: #232830;
    overflow: hidden;
}

.phase__track i {
    display: block;
    height: 100%;
    width: 0;
    border-radius: 999px;
    background: var(--accent);
    transition: width 0.35s var(--ease);
}

.phase.is-active .phase__track i {
    background: linear-gradient(90deg, var(--accent-deep), var(--accent));
}

.phase.is-done .phase__track i {
    background: var(--ok);
}

.phase__pct {
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-dim);
    text-align: right;
    font-variant-numeric: tabular-nums;
}

.phase.is-done .phase__pct {
    color: var(--ok);
}

.run__status {
    margin: 18px 0 0;
    font-size: 14px;
    color: var(--text-dim);
    min-height: 1.6em;
}

/* --- 完成态 --- */

.done__badge,
.error__badge {
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    margin-bottom: 16px;
}

.done__badge {
    background: rgba(92, 184, 127, 0.13);
    border: 1px solid rgba(92, 184, 127, 0.35);
    color: var(--ok);
}

.error__badge {
    background: var(--err-wash);
    border: 1px solid rgba(229, 100, 90, 0.35);
    color: var(--err);
}

.done__title,
.error__title {
    margin: 0 0 6px;
    font-size: 20px;
    font-weight: 620;
    letter-spacing: -0.01em;
}

.done__file {
    margin: 0 0 22px;
    font-family: var(--mono);
    font-size: 13px;
    color: var(--text-dim);
    word-break: break-all;
}

.error__msg {
    margin: 0;
    color: #f0b8b3;
    font-size: 14px;
    line-height: 1.75;
    max-width: 62ch;
}

.readout {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1px;
    margin: 0;
    border: 1px solid var(--line-soft);
    border-radius: var(--r-md);
    overflow: hidden;
    background: var(--line-soft);
}

.readout > div {
    padding: 14px 16px;
    background: var(--ink-900);
}

.readout dt {
    font-family: var(--mono);
    font-size: 10px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-faint);
    margin-bottom: 5px;
}

.readout dd {
    margin: 0;
    font-family: var(--mono);
    font-size: 14px;
    color: var(--text);
    font-variant-numeric: tabular-nums;
}

.done__note {
    margin: 16px 0 0;
    font-size: 13px;
    color: var(--text-faint);
}

.done__note b {
    font-family: var(--mono);
    color: var(--accent);
    font-weight: 600;
    font-variant-numeric: tabular-nums;
}

.done__note.is-expired b {
    color: var(--err);
}

/* ------------------------------------------------------------
   按钮
   ------------------------------------------------------------ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 22px;
    min-height: 44px;
    border: 1px solid transparent;
    border-radius: var(--r-md);
    font-family: inherit;
    font-size: 14px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease),
                color 0.18s var(--ease), transform 0.12s var(--ease);
}

.btn:active {
    transform: translateY(1px);
}

.btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.btn--primary {
    background: var(--accent);
    color: #1a1204;
}

.btn--primary:hover {
    background: #f5ae45;
}

.btn--ghost {
    background: transparent;
    border-color: var(--line);
    color: var(--text-dim);
}

.btn--ghost:hover {
    border-color: #3a4049;
    color: var(--text);
}

.btn[disabled],
.btn.is-busy {
    opacity: 0.55;
    pointer-events: none;
}

/* ------------------------------------------------------------
   内容区块
   ------------------------------------------------------------ */

.section {
    padding: 66px 0 0;
}

.section__title {
    margin: 0 0 26px;
    font-family: var(--mono);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--text-faint);
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 34px;
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: none;
}

.step__idx {
    display: block;
    font-family: var(--mono);
    font-size: 12px;
    letter-spacing: 0.12em;
    color: var(--accent);
    margin-bottom: 12px;
}

.step__title {
    margin: 0 0 8px;
    font-size: 17px;
    font-weight: 620;
    letter-spacing: -0.01em;
}

.step__copy {
    margin: 0;
    font-size: 14px;
    line-height: 1.78;
    color: var(--text-dim);
}

/* --- FAQ --- */

.faq {
    border-top: 1px solid var(--line-soft);
}

.faq__item {
    border-bottom: 1px solid var(--line-soft);
}

.faq__item summary {
    position: relative;
    padding: 20px 40px 20px 0;
    font-size: 15px;
    font-weight: 560;
    cursor: pointer;
    list-style: none;
    transition: color 0.18s var(--ease);
}

.faq__item summary::-webkit-details-marker {
    display: none;
}

.faq__item summary::after {
    content: "+";
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    font-family: var(--mono);
    font-size: 18px;
    color: var(--text-faint);
    transition: color 0.18s var(--ease), transform 0.22s var(--ease);
}

.faq__item[open] summary::after {
    content: "−";
    color: var(--accent);
}

.faq__item summary:hover {
    color: var(--accent);
}

.faq__item summary:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-radius: 4px;
}

.faq__item p {
    margin: 0 0 22px;
    max-width: 70ch;
    font-size: 14px;
    line-height: 1.82;
    color: var(--text-dim);
}

/* ------------------------------------------------------------
   页脚
   ------------------------------------------------------------ */

.site-foot {
    margin-top: 76px;
    border-top: 1px solid var(--line-soft);
    padding: 26px 0 40px;
}

.site-foot__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    font-size: 13px;
    color: var(--text-faint);
}

.site-foot__meta a {
    color: var(--text-dim);
    text-decoration: none;
    transition: color 0.18s var(--ease);
}

.site-foot__meta a:hover {
    color: var(--accent);
}

.site-foot__meta span[aria-hidden] {
    margin: 0 7px;
    opacity: 0.5;
}

/* ------------------------------------------------------------
   响应式
   ------------------------------------------------------------ */

@media (max-width: 860px) {
    .steps {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .readout {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 620px) {
    .wrap {
        padding: 0 18px;
    }

    .site-head__nav {
        gap: 16px;
        font-size: 13px;
    }

    .site-head__nav a:not(.site-head__admin) {
        display: none;
    }

    .hero {
        padding: 30px 0 26px;
    }

    .hero__title {
        font-size: clamp(27px, 8.4vw, 34px);
    }

    .tool__head {
        padding: 16px 18px;
    }

    .panel {
        padding: 20px 18px 22px;
    }

    .drop {
        padding: 38px 16px;
    }

    .fileline {
        flex-direction: column;
        gap: 4px;
    }

    .wave {
        height: 54px;
        gap: 1.5px;
    }

    .panel__actions .btn {
        flex: 1 1 auto;
    }

    .section {
        padding-top: 52px;
    }

    .site-foot__inner {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
}

/* ------------------------------------------------------------
   无障碍：尊重减弱动效偏好
   ------------------------------------------------------------ */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
        scroll-behavior: auto !important;
    }

    .panel {
        animation: none !important;
    }
}