/* Mobile-first, framework-free. Corporate/dashboard-style palette,
   responsive up to a centered desktop layout. */

:root {
    --color-bg: #f4f6f9;
    --color-surface: #ffffff;
    --color-border: #dfe3e8;
    --color-text: #1f2933;
    --color-text-muted: #616e7c;
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-success: #16a34a;
    --color-danger: #dc2626;
    --color-warning: #d97706;
    --radius: 10px;
    --shadow: 0 1px 3px rgba(16, 24, 40, 0.08), 0 1px 2px rgba(16, 24, 40, 0.06);
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

#app {
    max-width: 640px;
    margin: 0 auto;
    padding: 1.25rem 1rem 3rem;
}

.app-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.app-header h1 {
    margin: 0 0 0.25rem;
    font-size: 1.5rem;
    font-weight: 700;
}

.tagline {
    margin: 0;
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.screen {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem 1.25rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background-color 0.15s ease, border-color 0.15s ease, opacity 0.15s ease;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--color-primary);
    color: #fff;
}

.btn-primary:hover:not(:disabled) {
    background: var(--color-primary-hover);
}

.btn-secondary {
    background: var(--color-text);
    color: #fff;
}

.btn-outline {
    background: transparent;
    color: var(--color-text-muted);
    border-color: var(--color-border);
    width: auto;
    padding: 0.5rem 0.9rem;
    font-size: 0.85rem;
}

.divider {
    display: flex;
    align-items: center;
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.8rem;
    margin: 1.25rem 0;
}

.divider::before,
.divider::after {
    content: "";
    flex: 1;
    border-bottom: 1px solid var(--color-border);
}

.divider span {
    padding: 0 0.75rem;
}

.join-form {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.join-form label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-text-muted);
}

.join-form input {
    width: 100%;
    padding: 0.75rem;
    font-size: 1.1rem;
    letter-spacing: 0.15em;
    text-align: center;
    text-transform: uppercase;
    border: 1px solid var(--color-border);
    border-radius: 8px;
}

.join-form input:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 1px;
}

.error-text {
    color: var(--color-danger);
    font-size: 0.875rem;
    margin: 0.75rem 0 0;
}

.room-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}

.room-header h2 {
    margin: 0;
    font-size: 1.1rem;
}

.room-code {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    letter-spacing: 0.1em;
    color: var(--color-primary);
}

.connection-status {
    margin: 0.25rem 0 0;
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.connection-status[data-status="connected-direct"],
.connection-status[data-status="connected-relay"] {
    color: var(--color-success);
}

.connection-status[data-status="failed"] {
    color: var(--color-danger);
}

.connection-status[data-status="checking"],
.connection-status[data-status="connecting"] {
    color: var(--color-warning);
}

.device-panel h3,
.transfers-panel h3 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin: 0 0 0.5rem;
}

.device-list {
    list-style: none;
    margin: 0 0 1.25rem;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.device-list li {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 999px;
    padding: 0.35rem 0.75rem;
    font-size: 0.85rem;
}

.incoming-request {
    background: #fffbeb;
    border: 1px solid var(--color-warning);
    border-radius: var(--radius);
    padding: 1rem;
    margin-bottom: 1.25rem;
}

.incoming-request p {
    margin: 0 0 0.75rem;
    font-size: 0.9rem;
}

.incoming-request-actions {
    display: flex;
    gap: 0.5rem;
}

.incoming-request-actions .btn {
    width: auto;
    flex: 1;
}

.drop-zone {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius);
    padding: 2rem 1rem;
    text-align: center;
    color: var(--color-text-muted);
    margin-bottom: 1.25rem;
    transition: border-color 0.15s ease, background-color 0.15s ease;
}

.drop-zone.drag-over {
    border-color: var(--color-primary);
    background: rgba(37, 99, 235, 0.05);
}

.drop-zone p {
    margin: 0 0 0.75rem;
}

.drop-zone .btn {
    width: auto;
    padding: 0.6rem 1.25rem;
    margin: 0 auto;
}

.transfer-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.transfer-row {
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 0.75rem;
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 0.35rem 0.75rem;
    align-items: center;
}

.transfer-name {
    grid-column: 1 / 2;
    font-weight: 600;
    font-size: 0.9rem;
    overflow-wrap: anywhere;
}

.transfer-cancel-btn {
    grid-column: 2 / 3;
    grid-row: 1 / 3;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 0.35rem 0.65rem;
    font-size: 0.8rem;
    cursor: pointer;
    color: var(--color-danger);
}

.transfer-bar-track {
    grid-column: 1 / 2;
    background: var(--color-bg);
    border-radius: 999px;
    height: 8px;
    overflow: hidden;
}

.transfer-bar-fill {
    height: 100%;
    background: var(--color-primary);
    border-radius: 999px;
    transition: width 0.2s ease;
}

.transfer-meta {
    grid-column: 1 / 2;
    font-size: 0.78rem;
    color: var(--color-text-muted);
}

.transfer-done .transfer-bar-fill {
    background: var(--color-success);
}

.debug-panel {
    margin-top: 1.5rem;
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.debug-panel pre {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    background: var(--color-bg);
    border-radius: 6px;
    padding: 0.75rem;
}

@media (min-width: 480px) {
    .btn {
        width: auto;
    }

    .join-form {
        flex-direction: row;
        align-items: flex-end;
    }

    .join-form label {
        display: none;
    }

    .join-form input {
        flex: 1;
    }
}