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

:root {
    --bgDeep: #0d0f12;
    --bgPanel: #16191e;
    --bgElevated: #1d2128;
    --bgHover: #252a33;
    --border: #2a2f38;
    --borderLight: #353b46;
    --text: #e4e6eb;
    --textDim: #9aa0aa;
    --textMuted: #6b7280;
    --accent: #3b82f6;
    --accentHover: #4b8df7;
    --accentDim: #1e3a5f;
    --success: #22c55e;
    --warn: #f59e0b;
    --danger: #ef4444;
    --waveform: #4ade80;
    --waveformDim: #2a9d4a;
    --selection: rgba(59, 130, 246, 0.25);
    --playhead: #f59e0b;
    --segmentColors: #3b82f6, #22c55e, #f59e0b, #ec4899, #8b5cf6, #06b6d4, #ef4444, #84cc16;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
    background: var(--bgDeep);
    color: var(--text);
    font-size: 14px;
    user-select: none;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

.topBar {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 10px 20px;
    background: var(--bgPanel);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.brand {
    display: flex;
    align-items: center;
    gap: 8px;
}

.logoIcon {
    font-size: 22px;
}

.brand h1 {
    font-size: 17px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.toolbar {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
}

.fileNameLabel {
    color: var(--textDim);
    font-size: 13px;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    background: var(--bgElevated);
    border: 1px solid var(--borderLight);
    border-radius: 6px;
    color: var(--text);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.15s ease;
    white-space: nowrap;
}

.btn:hover:not(:disabled) {
    background: var(--bgHover);
    border-color: var(--accent);
}

.btn:active:not(:disabled) {
    transform: translateY(1px);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btnPrimary {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
}

.btnPrimary:hover:not(:disabled) {
    background: var(--accentHover);
    border-color: var(--accentHover);
}

.btnAccent {
    background: var(--success);
    border-color: var(--success);
    color: #0d0f12;
    font-weight: 600;
}

.btnAccent:hover:not(:disabled) {
    background: #2dd66e;
    border-color: #2dd66e;
}

.btnIcon {
    padding: 7px 10px;
    font-size: 16px;
}

.btnSmall {
    padding: 5px 10px;
    font-size: 13px;
    min-width: 36px;
    justify-content: center;
}

.btnIconInner {
    font-size: 14px;
}

.mainArea {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.waveformSection {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.waveformWrap {
    position: relative;
    flex: 1;
    background: var(--bgDeep);
    overflow: hidden;
    min-height: 0;
}

#waveformCanvas, #overlayCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: block;
}

#overlayCanvas {
    pointer-events: none;
}

.emptyHint {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: var(--textMuted);
    pointer-events: none;
}

.emptyIcon {
    font-size: 64px;
    margin-bottom: 16px;
    opacity: 0.4;
}

.emptyHint p {
    font-size: 16px;
    margin-bottom: 6px;
}

.subHint {
    font-size: 13px !important;
    color: var(--textMuted);
    opacity: 0.7;
}

.dragOverlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(59, 130, 246, 0.15);
    border: 3px dashed var(--accent);
    border-radius: 8px;
    display: none;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    z-index: 10;
    pointer-events: none;
}

.dragOverlay.show {
    display: flex;
}

.dragIcon {
    font-size: 56px;
    margin-bottom: 12px;
}

.dragText {
    font-size: 18px;
    color: var(--accent);
    font-weight: 600;
}

.waveformWrap.dragging {
    border-color: var(--accent);
}

.transportBar {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    background: var(--bgPanel);
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

.timeDisplay {
    display: flex;
    align-items: center;
    gap: 6px;
    font-family: "Consolas", "Courier New", monospace;
    font-size: 14px;
    color: var(--text);
    background: var(--bgDeep);
    padding: 6px 12px;
    border-radius: 5px;
    border: 1px solid var(--border);
}

.timeSep {
    color: var(--textMuted);
}

.zoomControls {
    display: flex;
    gap: 4px;
    margin-left: 8px;
}

.addSegmentArea {
    margin-left: auto;
}

.segmentsPanel {
    width: 340px;
    background: var(--bgPanel);
    border-left: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    flex-shrink: 0;
}

.panelHeader {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.panelHeader h2 {
    font-size: 15px;
    font-weight: 600;
}

.countBadge {
    background: var(--accentDim);
    color: var(--accent);
    padding: 2px 10px;
    border-radius: 10px;
    font-size: 12px;
    font-weight: 600;
}

.segmentList {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
}

.segmentList::-webkit-scrollbar {
    width: 8px;
}

.segmentList::-webkit-scrollbar-track {
    background: var(--bgPanel);
}

.segmentList::-webkit-scrollbar-thumb {
    background: var(--borderLight);
    border-radius: 4px;
}

.segmentList::-webkit-scrollbar-thumb:hover {
    background: var(--textMuted);
}

.emptySegmentHint {
    text-align: center;
    color: var(--textMuted);
    padding: 40px 20px;
    font-size: 13px;
    line-height: 1.8;
}

.segmentItem {
    background: var(--bgElevated);
    border: 1px solid var(--border);
    border-left: 3px solid var(--accent);
    border-radius: 6px;
    padding: 12px;
    margin-bottom: 10px;
    transition: all 0.15s ease;
}

.segmentItem:hover {
    border-color: var(--borderLight);
    background: var(--bgHover);
}

.segmentItem.playing {
    box-shadow: 0 0 0 1px var(--warn);
}

.segmentHeader {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 8px;
}

.segmentTitle {
    font-size: 13px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.segmentColorDot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    flex-shrink: 0;
}

.segmentActions {
    display: flex;
    gap: 4px;
}

.segmentActionBtn {
    width: 26px;
    height: 26px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--borderLight);
    border-radius: 4px;
    color: var(--textDim);
    cursor: pointer;
    font-size: 13px;
    transition: all 0.15s ease;
}

.segmentActionBtn:hover {
    color: var(--text);
    border-color: var(--accent);
    background: var(--bgHover);
}

.segmentActionBtn.danger:hover {
    color: var(--danger);
    border-color: var(--danger);
}

.segmentTimeRow {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 8px;
    font-family: "Consolas", monospace;
    font-size: 12px;
}

.timeInput {
    background: var(--bgDeep);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text);
    padding: 4px 6px;
    font-family: "Consolas", monospace;
    font-size: 12px;
    width: 80px;
    text-align: center;
}

.timeInput:focus {
    outline: none;
    border-color: var(--accent);
}

.timeArrow {
    color: var(--textMuted);
}

.segmentDuration {
    color: var(--textDim);
    margin-left: auto;
}

.segmentControls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.volumeControl {
    display: flex;
    align-items: center;
    gap: 8px;
    flex: 1;
}

.volumeLabel {
    font-size: 12px;
    color: var(--textDim);
}

.volumeSlider {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}

.volumeSlider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
}

.volumeSlider::-moz-range-thumb {
    width: 14px;
    height: 14px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

.volumeValue {
    font-size: 12px;
    color: var(--text);
    font-family: "Consolas", monospace;
    width: 42px;
    text-align: right;
}

.segmentExportBtn {
    padding: 5px 10px;
    font-size: 12px;
    background: var(--success);
    border: 1px solid var(--success);
    border-radius: 4px;
    color: #0d0f12;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
}

.segmentExportBtn:hover {
    background: #2dd66e;
}

.statusBar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 6px 16px;
    background: var(--bgPanel);
    border-top: 1px solid var(--border);
    font-size: 12px;
    color: var(--textDim);
    flex-shrink: 0;
}

#statusText {
    flex: 1;
}

.progressBar {
    width: 200px;
    height: 6px;
    background: var(--bgDeep);
    border-radius: 3px;
    overflow: hidden;
    border: 1px solid var(--border);
}

.progressFill {
    height: 100%;
    background: var(--accent);
    width: 0%;
    transition: width 0.2s ease;
    border-radius: 3px;
}

.toast {
    position: fixed;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bgElevated);
    border: 1px solid var(--borderLight);
    border-radius: 8px;
    padding: 12px 20px;
    color: var(--text);
    font-size: 13px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
    z-index: 1000;
    animation: toastIn 0.2s ease;
}

.toast.success {
    border-color: var(--success);
    color: var(--success);
}

.toast.error {
    border-color: var(--danger);
    color: var(--danger);
}

@keyframes toastIn {
    from { opacity: 0; transform: translate(-50%, 10px); }
    to { opacity: 1; transform: translate(-50%, 0); }
}

.btnPanelToggle {
    display: none;
    position: relative;
    background: var(--bgElevated);
    border-color: var(--borderLight);
}

.panelToggleBadge {
    position: absolute;
    top: -4px;
    right: -4px;
    background: var(--accent);
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    min-width: 16px;
    height: 16px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 4px;
}

.btnClosePanel {
    display: none;
    margin-left: auto;
    padding: 5px 10px;
    background: transparent;
    border: 1px solid var(--borderLight);
    border-radius: 4px;
    color: var(--textDim);
    font-size: 16px;
}

.btnClosePanel:hover {
    color: var(--danger);
    border-color: var(--danger);
}

.btnText {
    display: inline;
}

@media (max-width: 768px) {
    :root {
        font-size: 15px;
    }

    .topBar {
        padding: 8px 12px;
        gap: 8px;
        flex-wrap: wrap;
    }

    .brand h1 {
        font-size: 15px;
    }

    .logoIcon {
        font-size: 18px;
    }

    .toolbar {
        gap: 8px;
        flex-wrap: wrap;
    }

    .fileNameLabel {
        order: 3;
        flex-basis: 100%;
        font-size: 12px;
    }

    .btn {
        padding: 9px 14px;
        font-size: 14px;
    }

    .btnIcon {
        padding: 9px 12px;
        font-size: 18px;
    }

    .btnSmall {
        padding: 8px 12px;
        font-size: 15px;
        min-width: 42px;
    }

    .mainArea {
        flex-direction: column;
    }

    .waveformSection {
        flex: 1;
    }

    .waveformWrap {
        min-height: 180px;
    }

    .transportBar {
        padding: 8px 10px;
        gap: 6px;
        flex-wrap: wrap;
    }

    .timeDisplay {
        font-size: 13px;
        padding: 6px 10px;
        flex: 1;
        justify-content: center;
    }

    .zoomControls {
        gap: 4px;
    }

    .addSegmentArea {
        flex-basis: 100%;
        display: flex;
        gap: 8px;
    }

    .addSegmentArea .btn {
        flex: 1;
        justify-content: center;
    }

    .btnPanelToggle {
        display: inline-flex;
    }

    .segmentsPanel {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        width: 100%;
        height: 65vh;
        border-left: none;
        border-top: 1px solid var(--borderLight);
        border-radius: 12px 12px 0 0;
        transform: translateY(100%);
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: 100;
        box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.5);
    }

    .segmentsPanel.open {
        transform: translateY(0);
    }

    .panelHeader {
        padding: 12px 16px;
        cursor: pointer;
    }

    .btnClosePanel {
        display: inline-flex;
    }

    .segmentList {
        padding: 8px;
        padding-bottom: 20px;
    }

    .segmentItem {
        padding: 14px;
        margin-bottom: 12px;
    }

    .segmentActionBtn {
        width: 36px;
        height: 36px;
        font-size: 16px;
    }

    .timeInput {
        padding: 8px 6px;
        font-size: 14px;
        width: 90px;
    }

    .volumeSlider {
        height: 6px;
    }

    .volumeSlider::-webkit-slider-thumb {
        width: 22px;
        height: 22px;
    }

    .volumeSlider::-moz-range-thumb {
        width: 22px;
        height: 22px;
    }

    .statusBar {
        padding: 6px 12px;
        font-size: 11px;
    }

    .progressBar {
        width: 100px;
    }

    .toast {
        bottom: 20px;
        font-size: 14px;
        padding: 14px 24px;
        max-width: 90vw;
    }

    .emptyHint p {
        font-size: 15px;
    }

    .subHint {
        font-size: 12px !important;
    }
}

@media (max-width: 480px) {
    .brand h1 {
        font-size: 14px;
    }

    .btnText {
        display: none;
    }

    .addSegmentArea .btn {
        font-size: 14px;
    }

    .timeDisplay {
        font-size: 12px;
    }

    .segmentTimeRow {
        flex-wrap: wrap;
    }
}

@media (max-height: 500px) and (orientation: landscape) {
    .topBar {
        padding: 4px 12px;
    }

    .waveformWrap {
        min-height: 100px;
    }

    .segmentsPanel {
        height: 80vh;
    }
}