:root {
    /* Měkký, estetický světlý motiv (výchozí) */
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #2d3748;
    --text-sub: #718096;
    --primary: #f43f5e;
    --primary-hover: #e11d48;
    --border-color: #e2e8f0;
    --day-empty: #f1f5f9;
    --day-hover: #e2e8f0;
    --overlay-bg: rgba(255,255,255,0.6);
    
    --color-menstruation: #e11d48;
    --color-ovulation: #8b5cf6;
    --color-note: #3b82f6;
    --color-predicted: rgba(225, 29, 72, 0.15);
}

:root.dark {
    --bg-color: #121214;
    --card-bg: #1e1e24;
    --text-main: #f0f0f5;
    --text-sub: #a0a0ab;
    --border-color: #33333b;
    --day-empty: #27272a;
    --day-hover: #3f3f46;
    --overlay-bg: rgba(0,0,0,0.7);
    --color-predicted: rgba(251, 113, 133, 0.4);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Outfit', sans-serif; background-color: var(--bg-color); color: var(--text-main); display: flex; justify-content: center; min-height: 100vh; transition: background-color 0.3s, color 0.3s; }
.container { width: 100%; max-width: 1400px; padding: 20px; }
.hidden { display: none !important; }
#login-container { display: flex; align-items: center; justify-content: center; height: 100vh; }
.login-card { background-color: var(--card-bg); padding: 40px; border-radius: 16px; box-shadow: 0 4px 20px rgba(0,0,0,0.05); text-align: center; width: 100%; max-width: 400px; border: 1px solid var(--border-color); }
.login-card h1 { margin-bottom: 24px; color: var(--primary); }
input, select, textarea { width: 100%; padding: 12px; margin-bottom: 16px; background-color: var(--card-bg); border: 1px solid var(--border-color); border-radius: 8px; color: var(--text-main); font-family: inherit; font-size: 1rem; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--primary); }
button { width: 100%; padding: 12px; background-color: var(--primary); color: #fff; border: none; border-radius: 8px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: background-color 0.2s, transform 0.1s; }
button:hover { background-color: var(--primary-hover); }
button:active { transform: scale(0.98); }
.error { color: var(--color-menstruation); margin-top: 10px; font-size: 0.9rem; }
.navbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 30px; padding-bottom: 20px; border-bottom: 1px solid var(--border-color); }
.navbar h1 { color: var(--primary); font-weight: 600; letter-spacing: 1px; }
.nav-controls { display: flex; align-items: center; gap: 15px; }
.nav-controls span { font-size: 1.2rem; font-weight: 600; }
.nav-controls button { width: auto; padding: 8px 16px; min-width: 44px; }
.btn-outline { background-color: transparent; border: 1px solid var(--border-color); color: var(--text-main); }
.btn-outline:hover { background-color: var(--day-hover); color: var(--text-main); }
.calendar-wrapper { overflow-x: auto; padding-bottom: 20px; margin-right: -10px; padding-right: 10px; }
#calendar-grid { display: flex; flex-direction: column; gap: 8px; width: max-content; min-width: 100%; padding-right: 20px; }
.month-row { display: flex; align-items: center; }
.month-label { width: 90px; font-weight: 600; color: var(--text-sub); text-transform: uppercase; font-size: 0.9rem; flex-shrink: 0; }
.days-container { display: flex; gap: 4px; flex-grow: 1; flex-wrap: wrap; }
.day-sq { width: 32px; height: 32px; background-color: var(--day-empty); border: 1px solid var(--border-color); border-radius: 6px; display: flex; align-items: center; justify-content: center; font-size: 0.8rem; color: var(--text-sub); cursor: pointer; transition: all 0.2s; user-select: none; position: relative; flex-shrink: 0; }
.day-sq:hover { background-color: var(--day-hover); border-color: var(--primary); transform: scale(1.1); z-index: 10; font-weight: bold; }
.day-sq.type-menstruation { background-color: var(--color-menstruation); color: #fff; font-weight: bold; border-color: var(--color-menstruation); }
.day-sq.type-ovulation { border: 2px solid var(--color-ovulation); color: var(--color-ovulation); font-weight: bold; background-color: var(--card-bg); }
.day-sq.type-note { background-color: var(--color-note); color: #fff; border-color: var(--color-note); }
.day-sq.type-predicted { background-color: var(--color-predicted); font-style: italic; border: 1px dashed var(--primary); color: var(--primary); }
.day-sq.has-note::after { content: ''; position: absolute; top: 4px; right: 4px; width: 6px; height: 6px; background: #fff; border-radius: 50%; box-shadow: 0 1px 2px rgba(0,0,0,0.2); }
.day-sq:not(.type-menstruation):not(.type-note).has-note::after { background: var(--color-note); }

.day-sq.intensity-1 { opacity: 0.5; }
.day-sq.intensity-2 { opacity: 0.7; }
.day-sq.intensity-3 { opacity: 0.85; }
.day-sq.intensity-4 { opacity: 1.0; box-shadow: 0 0 8px rgba(225,29,72,0.4); }

.day-sq.invisible { display: none; } /* Better than visibility: hidden for mobile wrapping */

/* Today highlight */
.day-sq.today-highlight {
    outline: 2px solid var(--primary);
    outline-offset: -2px;
    font-weight: bold;
    color: var(--primary);
}
.day-sq.type-menstruation.today-highlight { color: #fff; }
.day-sq.type-note.today-highlight { color: #fff; }

.modal { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: var(--overlay-bg); display: flex; align-items: center; justify-content: center; z-index: 100; backdrop-filter: blur(4px); transition: background-color 0.3s; }
.modal-content { background-color: var(--card-bg); padding: 30px; border-radius: 16px; width: 90%; max-width: 400px; box-shadow: 0 10px 40px rgba(0,0,0,0.1); border: 1px solid var(--border-color); }
.modal-content h2 { margin-bottom: 20px; color: var(--text-main); }
.modal-actions { display: flex; gap: 10px; margin-top: 20px; }
.btn-secondary { background-color: var(--day-empty); color: var(--text-main); border: 1px solid var(--border-color); }
.btn-secondary:hover { background-color: var(--day-hover); }

/* Mobile wrapping */
@media (max-width: 768px) {
    #calendar-grid { width: 100%; }
    .month-row { display: block; padding-bottom: 15px; margin-bottom: 15px; border-bottom: 1px solid var(--border-color); }
    .month-label { width: 100%; margin-bottom: 8px; }
    .navbar { flex-wrap: wrap; gap: 15px; }
    .nav-controls { flex-wrap: wrap; }
}