:root {
    --bg: #eceff1;
    --card-bg: #ffffff;
    --primary: #0288d1;
    --primary-hover: #0277bd;
    --success: #2e7d32;
    --success-hover: #1b5e20;
    --danger: #c62828;
    --danger-hover: #b71c1c;
    --text-primary: #263238;
    --text-secondary: #546e7a;
    --border: #cfd8dc;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
}

body {
    background-color: var(--bg);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 16px;
}

.tarjeta-captura {
    background: var(--card-bg);
    width: 100%;
    max-width: 520px;
    border-radius: 12px;
    padding: 26px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--border);
}

.tarjeta-captura h1 {
    font-size: 22px;
    color: var(--primary);
    margin-bottom: 4px;
    text-align: center;
}

.tarjeta-captura .subtitulo {
    font-size: 13px;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 22px;
}

.campo {
    margin-bottom: 14px;
}

.campo label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 5px;
}

.campo input,
.campo select {
    width: 100%;
    padding: 10px 12px;
    font-size: 14px;
    border: 1px solid var(--border);
    border-radius: 6px;
    outline: none;
    transition: border-color 0.2s;
    background-color: #fafafa;
}

.campo input:focus,
.campo select:focus {
    border-color: var(--primary);
    background-color: #ffffff;
}

.fila-doble {
    display: flex;
    gap: 12px;
}

.fila-doble .campo {
    flex: 1;
}

.seccion-reloj {
    background-color: #f5f7f8;
    border: 2px dashed #b0bec5;
    border-radius: 8px;
    padding: 18px;
    text-align: center;
    margin: 18px 0;
}

.cronometro {
    font-size: 44px;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    color: #0d47a1;
    margin-bottom: 12px;
}

.botones-cronometro {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.btn {
    padding: 10px 18px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s, opacity 0.2s;
}

.btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

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

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

.btn-detener {
    background-color: var(--danger);
    color: #ffffff;
}

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

.btn-guardar {
    width: 100%;
    padding: 12px;
    font-size: 15px;
    background-color: var(--success);
    color: #ffffff;
}

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

.alerta {
    margin-top: 14px;
    padding: 10px 14px;
    font-size: 13px;
    border-radius: 6px;
    text-align: center;
    display: none;
}

.alerta.exito {
    display: block;
    background-color: #e8f5e9;
    color: var(--success);
    border: 1px solid #c8e6c9;
}

.alerta.error {
    display: block;
    background-color: #ffebee;
    color: var(--danger);
    border: 1px solid #ffcdd2;
}