:root {
    --card: #ffffff;
    --border: #e3e8f2;
    --primary-text: #0f172a;
    --secondary-text: #475569;
    --success: #0f9d58;
    --danger: #b91c1c;
    --accent: #2563eb;
    --accent-secondary: #4338ca;
    --accent-soft: #eef2ff;
    --page-bg: radial-gradient(circle at 20% 20%, #eef2ff, #f5f7fb 45%, #edf5ff 100%);
    --thread-bg: #f8fafc;
    --callout-bg: #f1f5ff;
    --spinner-color: #dbeafe;
    --focus-ring-color: rgba(37, 99, 235, 0.2);
    --shadow-color: rgba(37, 99, 235, 0.25);
}

body {
    margin: 0;
    font-family: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
    background: var(--page-bg);
    color: var(--primary-text);
    padding: 48px 16px 80px;
}

body.theme-existing {
    --accent: #4338ca;
    --accent-secondary: #6d28d9;
    --accent-soft: #f0e9ff;
    --callout-bg: #f4efff;
}

body.theme-new {
    --accent: #0ea5e9;
    --accent-secondary: #0284c7;
    --accent-soft: #e0f7ff;
    --callout-bg: #e0f7ff;
    --spinner-color: #cffafe;
    --focus-ring-color: rgba(14, 165, 233, 0.2);
    --shadow-color: rgba(14, 165, 233, 0.25);
}

* {
    box-sizing: border-box;
}

.page {
    max-width: 1100px;
    margin: 0 auto;
}

.hero {
    text-align: center;
    margin-bottom: 36px;
}

.hero .eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 13px;
    color: var(--secondary-text);
}

.hero h1 {
    margin: 12px 0 8px;
    font-size: 32px;
}

.hero p {
    margin: 0 auto;
    max-width: 720px;
    color: var(--secondary-text);
    line-height: 1.6;
}

.layout {
    display: grid;
    grid-template-columns: minmax(0, 1.8fr) minmax(260px, 1fr);
    gap: 28px;
}

.form-card,
.side-panel,
.success-card {
    background: var(--card);
    border-radius: 20px;
    padding: 32px;
    border: 1px solid var(--border);
    box-shadow: 0 25px 55px rgba(15, 23, 42, 0.08);
}

.form-card h2,
.success-card h2 {
    margin: 0 0 8px;
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 999px;
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
}

.alert {
    display: none;
    margin: 20px 0;
    padding: 12px 16px;
    border-radius: 12px;
    font-size: 14px;
}

.alert.error {
    display: block;
    border: 1px solid rgba(185, 28, 28, 0.2);
    background: rgba(248, 113, 113, 0.1);
    color: var(--danger);
}

.form-grid {
    display: grid;
    gap: 20px;
}

.split {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

label {
    font-weight: 600;
    font-size: 14px;
    display: block;
    margin-bottom: 6px;
}

input,
select,
textarea {
    width: 100%;
    padding: 12px 14px;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: #fefefe;
    font-size: 14px;
    transition: border 0.2s ease, box-shadow 0.2s ease;
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--focus-ring-color);
}

.hint {
    margin-top: 6px;
    font-size: 13px;
    color: var(--secondary-text);
}

.file-input input[type="file"] {
    padding: 10px;
    background: #f8fafc;
    border: 1px dashed var(--border);
}

.file-input input[type="file"]::file-selector-button {
    background: var(--accent);
    color: #fff;
    border: none;
    padding: 8px 16px;
    border-radius: 8px;
    font-weight: 600;
    margin-right: 16px;
    cursor: pointer;
}

.primary-btn {
    width: 100%;
    margin-top: 12px;
    padding: 16px 18px;
    border: none;
    border-radius: 14px;
    font-size: 16px;
    font-weight: 600;
    color: #fff;
    background: linear-gradient(135deg, var(--accent-secondary), var(--accent));
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

.primary-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 15px 30px var(--shadow-color);
}

.primary-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.spinner {
    display: none;
    font-size: 14px;
    color: var(--spinner-color);
}

.side-panel h3 {
    margin-top: 0;
    font-size: 20px;
}

.side-panel ul,
.side-panel ol {
    padding-left: 20px;
    color: var(--secondary-text);
    line-height: 1.8;
    margin-bottom: 20px;
}

.side-panel .callout {
    background: var(--callout-bg);
    border-radius: 12px;
    padding: 16px;
    color: var(--accent);
    font-weight: 600;
    font-size: 14px;
}

.success-card {
    display: none;
    grid-column: 1 / -1;
    text-align: center;
}

.success-card.active {
    display: block;
}

.success-icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: 2px solid var(--success);
    margin: 0 auto 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--success);
}

.thread-info {
    margin-top: 20px;
    padding: 16px;
    border-radius: 12px;
    border: 1px dashed var(--border);
    background: var(--thread-bg);
}

.back-link {
    display: inline-block;
    margin-top: 24px;
    color: var(--accent);
    font-weight: 600;
    text-decoration: none;
}

@media (max-width: 960px) {
    .layout {
        grid-template-columns: 1fr;
    }
}