* {
            box-sizing: border-box;
        }

        body {
            margin: 0;
            min-height: 100vh;
            font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text);
            background:
                radial-gradient(circle at 15% 10%, rgba(255, 255, 255, 0.5), transparent 28%),
                radial-gradient(circle at 88% 18%, var(--bg-2), transparent 32%),
                linear-gradient(140deg, var(--bg), var(--bg-2));
            overflow-x: hidden;
        }

        body::before,
        body::after {
            content: "";
            position: fixed;
            width: 360px;
            height: 360px;
            border-radius: 50%;
            pointer-events: none;
            filter: blur(24px);
            opacity: 0.28;
            z-index: 0;
        }

        body::before {
            left: -140px;
            bottom: 8%;
            background: var(--primary-2);
        }

        body::after {
            right: -150px;
            top: 18%;
            background: var(--accent);
        }

        button,
        select,
        input::file-selector-button {
            font: inherit;
        }

        .pill,
        .nav-btn,
        .ghost-btn,
        .primary-btn,
        .mode-card,
        .small-btn {
            border: 0;
            cursor: pointer;
            transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, opacity 0.18s ease;
        }

        .pill,
        .nav-btn,
        .ghost-btn,
        .small-btn {
            background: var(--card);
            color: var(--text);
            border: 1px solid rgba(255, 255, 255, 0.28);
            backdrop-filter: blur(16px);
        }

        .pill {
            padding: 9px 12px;
            border-radius: 999px;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            color: var(--muted);
            font-size: 13px;
        }

        .pill select {
            border: 0;
            background: transparent;
            color: var(--text);
            outline: none;
        }

        .nav-btn,
        .small-btn {
            border-radius: 999px;
            padding: 10px 14px;
            color: var(--text);
        }

        .nav-btn.active {
            background: var(--primary);
            color: white;
            box-shadow: 0 14px 28px var(--ring);
        }

        .screen {
            display: none;
        }

        .screen.active {
            display: block;
            animation: fadeIn 0.28s ease both;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(8px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .panel {
            background: var(--card);
            border: 1px solid rgba(255, 255, 255, 0.34);
            box-shadow: var(--shadow);
            border-radius: 32px;
            backdrop-filter: blur(22px);
        }

        .mode-card:hover,
        .primary-btn:hover,
        .small-btn:hover,
        .ghost-btn:hover,
        .nav-btn:hover {
            transform: translateY(-2px);
        }

        .duration {
            margin-top: 18px;
            display: inline-flex;
            width: fit-content;
            padding: 7px 10px;
            border-radius: 999px;
            background: var(--accent);
            color: var(--primary);
            font-weight: 700;
            font-size: 13px;
        }

        .primary-btn,
        .ghost-btn {
            border-radius: 999px;
            padding: 12px 18px;
        }

        .primary-btn {
            background: var(--primary);
            color: white;
            box-shadow: 0 14px 30px var(--ring);
        }

        .ghost-btn {
            color: var(--text);
        }

        .hidden-input {
            display: none;
        }

        .toast {
            position: fixed;
            left: 50%;
            bottom: 24px;
            transform: translateX(-50%) translateY(30px);
            background: var(--card-strong);
            color: var(--text);
            padding: 12px 16px;
            border-radius: 999px;
            box-shadow: var(--shadow);
            opacity: 0;
            pointer-events: none;
            transition: all 0.25s ease;
            z-index: 99;
            max-width: calc(100% - 40px);
            text-align: center;
        }

        .toast.show {
            transform: translateX(-50%) translateY(0);
            opacity: 1;
        }

        .completion {
            display: none;
            position: fixed;
            inset: 0;
            z-index: 50;
            background: rgba(0, 0, 0, 0.28);
            backdrop-filter: blur(14px);
            align-items: center;
            justify-content: center;
            padding: 24px;
        }

        .completion.show {
            display: flex;
        }

        .completion-card {
            width: min(520px, 100%);
            padding: 34px;
            border-radius: 34px;
            background: var(--card-strong);
            box-shadow: var(--shadow);
            text-align: center;
        }

        .completion-card .check {
            width: 74px;
            height: 74px;
            border-radius: 50%;
            margin: 0 auto 18px;
            background: var(--primary);
            color: white;
            display: grid;
            place-items: center;
            font-size: 36px;
            box-shadow: 0 18px 34px var(--ring);
        }

        .completion-card h2 {
            margin: 0;
            font-size: 32px;
            letter-spacing: -0.05em;
        }

        .completion-card p {
            color: var(--muted);
            line-height: 1.8;
        }

        .info-link {
            margin-top: 10px;
            width: fit-content;
            border: 0;
            border-radius: 999px;
            padding: 8px 12px;
            background: var(--accent);
            color: var(--primary);
            font-weight: 700;
            cursor: pointer;
        }

        .help-modal {
            display: none;
            position: fixed;
            inset: 0;
            z-index: 55;
            background: rgba(0, 0, 0, 0.28);
            backdrop-filter: blur(14px);
            align-items: center;
            justify-content: center;
            padding: 24px;
        }

        .help-modal.show {
            display: flex;
        }

        .help-card {
            width: min(560px, 100%);
            padding: 32px;
            border-radius: 32px;
            background: var(--card-strong);
            box-shadow: var(--shadow);
        }

        .help-card h2 {
            margin: 0 0 12px;
            font-size: 28px;
            letter-spacing: -0.04em;
        }

        .help-card p,
        .help-card li {
            color: var(--muted);
            line-height: 1.8;
        }

        .help-card ol {
            padding-left: 22px;
            margin: 14px 0 18px;
        }

        .footer-note {
            margin-top: 24px;
            color: var(--muted);
            font-size: 13px;
            line-height: 1.7;
            text-align: center;
        }