:root {
    --bg: #f6f8fb;
    --surface: #ffffff;
    --surface-muted: #f9fafb;
    --text: #1f2937;
    --muted: #667085;
    --border: #d9e0e8;
    --border-strong: #b8c2cc;
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --success: #0f766e;
    --success-bg: #ecfdf5;
    --warning: #b45309;
    --warning-bg: #fff7ed;
    --danger: #b42318;
    --danger-bg: #fff1f0;
    --shadow: 0 18px 45px rgba(31, 41, 55, 0.10);
}

* {
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    margin: 0;
    color: var(--text);
    background:
        linear-gradient(180deg, #ffffff 0, var(--bg) 250px),
        var(--bg);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.5;
}

a {
    color: inherit;
}

.page-shell {
    width: min(920px, calc(100% - 32px));
    margin: 0 auto;
    padding: 28px 0 44px;
}

.home-shell {
    width: min(780px, calc(100% - 32px));
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 24px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--text);
    font-size: 18px;
    font-weight: 700;
    text-decoration: none;
}

.brand-mark {
    display: inline-grid;
    width: 34px;
    height: 34px;
    place-items: center;
    color: #ffffff;
    background: var(--success);
    border-radius: 8px;
    font-size: 15px;
    letter-spacing: 0;
}

.nav {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
}

.nav a {
    min-width: 64px;
    padding: 8px 12px;
    color: var(--muted);
    border-radius: 6px;
    text-align: center;
    text-decoration: none;
    font-size: 14px;
}

.nav a:hover,
.nav a.active {
    color: var(--text);
    background: var(--surface-muted);
}

.panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.panel-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 20px;
    padding: 28px 30px 22px;
    border-bottom: 1px solid var(--border);
}

.panel-body {
    padding: 28px 30px 30px;
}

.eyebrow {
    margin: 0 0 6px;
    color: var(--success);
    font-size: 13px;
    font-weight: 700;
}

h1 {
    margin: 0;
    color: var(--text);
    font-size: 30px;
    line-height: 1.18;
    letter-spacing: 0;
}

h3 {
    margin: 0 0 18px;
    font-size: 18px;
    line-height: 1.3;
}

.form-grid {
    display: grid;
    gap: 18px;
}

.form-group {
    margin: 0;
}

label {
    display: block;
    margin-bottom: 8px;
    color: #344054;
    font-size: 14px;
    font-weight: 700;
}

.field-meta {
    margin-top: 8px;
    color: var(--muted);
    font-size: 13px;
}

.field-meta.over-limit {
    color: var(--danger);
    font-weight: 700;
}

input[type="file"],
input[type="number"],
input[type="text"],
textarea {
    width: 100%;
    padding: 10px 12px;
    color: var(--text);
    background: #ffffff;
    border: 1px solid var(--border-strong);
    border-radius: 8px;
    font: inherit;
    outline: none;
}

input[type="file"],
input[type="number"],
input[type="text"] {
    min-height: 44px;
}

input[type="file"] {
    padding: 8px 12px;
}

textarea {
    min-height: 260px;
    resize: vertical;
}

input:focus,
textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.14);
}

.actions,
.home-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.actions {
    margin-top: 22px;
}

.button,
button,
.btn,
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    padding: 10px 16px;
    color: #ffffff;
    background: var(--primary);
    border: 1px solid var(--primary);
    border-radius: 8px;
    cursor: pointer;
    font: inherit;
    font-size: 15px;
    font-weight: 700;
    text-decoration: none;
}

.button:hover,
button:hover,
.btn:hover,
.download-btn:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
}

.button.secondary,
.btn-secondary {
    background: var(--success);
    border-color: var(--success);
}

.button.secondary:hover,
.btn-secondary:hover {
    background: #0b5f58;
    border-color: #0b5f58;
}

button:disabled {
    color: #f8fafc;
    background: #98a2b3;
    border-color: #98a2b3;
    cursor: not-allowed;
}

.ghost-link,
.back-btn {
    display: inline-flex;
    align-items: center;
    min-height: 38px;
    padding: 8px 12px;
    color: var(--muted);
    background: #ffffff;
    border: 1px solid var(--border);
    border-radius: 8px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 700;
}

.ghost-link:hover,
.back-btn:hover {
    color: var(--text);
    border-color: var(--border-strong);
}

.progress-container {
    display: none;
    margin-top: 22px;
    padding: 16px;
    background: var(--surface-muted);
    border: 1px solid var(--border);
    border-radius: 8px;
}

.progress-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 10px;
}

.progress-row label {
    margin: 0;
}

#progressText {
    color: var(--muted);
    font-size: 14px;
    font-weight: 700;
}

progress {
    width: 100%;
    height: 10px;
    overflow: hidden;
    border: 0;
    border-radius: 999px;
    background: #e5e7eb;
}

progress::-webkit-progress-bar {
    background: #e5e7eb;
    border-radius: 999px;
}

progress::-webkit-progress-value {
    background: var(--success);
    border-radius: 999px;
}

progress::-moz-progress-bar {
    background: var(--success);
    border-radius: 999px;
}

.error,
.notice {
    display: none;
    margin-top: 18px;
    padding: 12px 14px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 700;
}

.error {
    color: var(--danger);
    background: var(--danger-bg);
    border: 1px solid #ffccc7;
}

.notice {
    display: block;
    color: var(--warning);
    background: var(--warning-bg);
    border: 1px solid #fed7aa;
}

.result {
    display: none;
    margin-top: 24px;
    padding: 20px;
    background: var(--success-bg);
    border: 1px solid #a7f3d0;
    border-radius: 8px;
}

.result-grid {
    display: grid;
    gap: 14px;
}

.url-display {
    min-height: 42px;
    margin-top: 0;
    padding: 10px 12px;
    color: #233044;
    background: #ffffff;
    border: 1px solid var(--border);
    border-radius: 8px;
    word-break: break-all;
    font-size: 14px;
}

.code-display {
    display: inline-flex;
    align-items: center;
    min-height: 48px;
    padding: 8px 14px;
    color: #083344;
    background: #ffffff;
    border: 1px solid #99f6e4;
    border-radius: 8px;
    font-size: 28px;
    font-weight: 800;
    letter-spacing: 0;
}

.home-panel {
    padding: 36px;
}

.home-panel h1 {
    margin-bottom: 26px;
}

.home-actions {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.home-action {
    min-height: 120px;
    align-items: flex-start;
    padding: 22px;
    color: var(--text);
    background: #ffffff;
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: 0 10px 24px rgba(31, 41, 55, 0.06);
    text-align: left;
}

.home-action strong {
    display: block;
    margin-bottom: 8px;
    font-size: 20px;
}

.home-action span {
    color: var(--muted);
    font-size: 14px;
    font-weight: 600;
}

.home-action:hover {
    border-color: var(--primary);
    transform: translateY(-1px);
}

.empty-panel {
    padding: 32px;
}

@media (max-width: 640px) {
    .page-shell {
        width: min(100% - 24px, 920px);
        padding: 18px 0 30px;
    }

    .topbar,
    .panel-header {
        align-items: stretch;
        flex-direction: column;
    }

    .panel-header,
    .panel-body,
    .home-panel,
    .empty-panel {
        padding: 22px;
    }

    .nav {
        width: 100%;
    }

    .nav a {
        flex: 1;
    }

    h1 {
        font-size: 26px;
    }

    .actions,
    .home-actions {
        grid-template-columns: 1fr;
    }

    .button,
    button,
    .btn,
    .download-btn,
    .ghost-link,
    .back-btn {
        width: 100%;
    }
}