:root {
    --color-primary: #2391db;
    --color-accent: #00bcd4;
    --color-text: #34343c;
    --color-border: #ebeef6;
}

body {
    font-family: 'Roboto', Arial, sans-serif;
    font-weight: 300;
    font-size: 15px;
    line-height: 1.4;
    color: var(--color-text);
}

.btn-primary {
    background-color: var(--color-primary);
    color: #fff;
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 400;
    cursor: pointer;
    transition: background-color 0.2s;
    display: inline-block;
    text-align: center;
    text-decoration: none;
}

.btn-primary:hover {
    background-color: #1a7cc0;
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text);
    padding: 12px 24px;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    font-size: 15px;
    font-weight: 400;
    cursor: pointer;
    transition: border-color 0.2s;
    display: inline-block;
    text-align: center;
    text-decoration: none;
}

.btn-secondary:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    font-size: 15px;
    font-family: 'Roboto', Arial, sans-serif;
    color: var(--color-text);
    transition: border-color 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(35, 145, 219, 0.1);
}

.alert-error {
    background: #fef2f2;
    border: 1px solid #fecaca;
    color: #dc2626;
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 14px;
}

.alert-success {
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    color: #16a34a;
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 14px;
}

.day-card {
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 16px;
    cursor: pointer;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.day-card:hover:not(.day-card--full) {
    border-color: var(--color-primary);
    box-shadow: 0 2px 8px rgba(35, 145, 219, 0.1);
}

.day-card--full {
    opacity: 0.4;
    cursor: not-allowed;
}

.day-card--selected {
    border-color: var(--color-primary);
    background: rgba(35, 145, 219, 0.05);
}