/* ============================================================
   RESET & BASES
   ============================================================ */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-gradient: linear-gradient(135deg, #1e293b, #334155);
    --card-bg: #ffffff;
    --card-border: #e5e7eb;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --accent: #2563eb;
    --accent-light: #3b82f6;
    --accent-hover: #1d4ed8;
    --green: #16a34a;
    --orange: #ca8a04;
    --red: #dc2626;
    --input-bg: #f9fafb;
    --input-border: #d1d5db;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.12);
    --task-bg: #f9fafb;
    --header-bg: rgba(255,255,255,0.95);
    --history-bg: #f3f4f6;
    --stat-total-bg: #e0e7ff;
    --stat-total-color: #3730a3;
    --stat-done-bg: #dcfce7;
    --stat-done-color: #166534;
    --stat-remaining-bg: #fef9c3;
    --stat-remaining-color: #854d0e;
    --tag-haute-bg: #fee2e2;
    --tag-haute-color: #991b1b;
    --tag-moyenne-bg: #fef3c7;
    --tag-moyenne-color: #92400e;
    --tag-basse-bg: #dcfce7;
    --tag-basse-color: #166534;
}

/* Mode sombre */
body.dark-mode {
    --bg-gradient: linear-gradient(135deg, #020617, #0f172a);
    --card-bg: #111827;
    --card-border: #1f2933;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --input-bg: #020617;
    --input-border: #374151;
    --shadow: 0 8px 32px rgba(0,0,0,0.6);
    --shadow-hover: 0 12px 40px rgba(0,0,0,0.8);
    --task-bg: #020617;
    --header-bg: rgba(2, 6, 23, 0.95);
    --history-bg: #111827;
    --stat-total-bg: #1e293b;
    --stat-total-color: #93c5fd;
    --stat-done-bg: #052e16;
    --stat-done-color: #4ade80;
    --stat-remaining-bg: #422006;
    --stat-remaining-color: #facc15;
    --tag-haute-bg: #450a0a;
    --tag-haute-color: #f87171;
    --tag-moyenne-bg: #422006;
    --tag-moyenne-color: #facc15;
    --tag-basse-bg: #052e16;
    --tag-basse-color: #4ade80;
}

body {
    font-family: 'DM Sans', sans-serif;
    min-height: 100vh;
    background: var(--bg-gradient);
    transition: background 0.4s ease;
}

.hidden { display: none !important; }


/* ============================================================
   PAGE AUTHENTIFICATION
   ============================================================ */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.auth-bg-shape {
    position: absolute;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(124,58,237,0.25) 0%, transparent 70%);
    top: -100px;
    right: -100px;
    pointer-events: none;
}

.auth-card {
    background: var(--card-bg);
    width: 100%;
    max-width: 420px;
    border-radius: 20px;
    padding: 40px 36px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.35);
    animation: fadeUp 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    z-index: 1;
}

.auth-header {
    text-align: center;
    margin-bottom: 28px;
}

.auth-logo {
    font-size: 2.2rem;
    color: var(--accent);
    display: block;
    margin-bottom: 8px;
}

.auth-header h1 {
    font-family: 'Syne', sans-serif;
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -1px;
}

.auth-header h1 span {
    color: var(--accent);
}

.auth-subtitle {
    color: var(--text-muted);
    font-size: 0.88rem;
    margin-top: 6px;
}

/* Onglets */
.auth-tabs {
    display: flex;
    background: var(--input-bg);
    border-radius: 10px;
    padding: 4px;
    margin-bottom: 24px;
    border: 1px solid var(--input-border);
}

.tab-btn {
    flex: 1;
    padding: 10px;
    border: none;
    background: transparent;
    border-radius: 7px;
    font-family: 'DM Sans', sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.25s ease;
}

.tab-btn.active {
    background: var(--accent);
    color: white;
    box-shadow: 0 2px 8px rgba(91,33,182,0.35);
}

/* Formulaires */
.auth-form {
    display: none;
    flex-direction: column;
    gap: 16px;
}

.auth-form.active {
    display: flex;
    animation: fadeIn 0.3s ease;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

input[type="text"],
input[type="email"],
input[type="password"],
select {
    padding: 12px 14px;
    border: 1.5px solid var(--input-border);
    border-radius: 10px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-family: 'DM Sans', sans-serif;
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.25s, box-shadow 0.25s;
}

input:focus, select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(91,33,182,0.12);
}

.btn-primary {
    padding: 14px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 10px;
    font-family: 'Syne', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: background 0.25s, transform 0.1s, box-shadow 0.25s;
    letter-spacing: 0.02em;
    margin-top: 4px;
}

.btn-primary:hover {
    background: var(--accent-hover);
    box-shadow: 0 4px 16px rgba(91,33,182,0.35);
}

.btn-primary:active {
    transform: scale(0.97);
}

.error-msg {
    color: var(--red);
    font-size: 0.83rem;
    min-height: 18px;
    font-weight: 500;
}

.success-msg {
    color: var(--green);
    font-size: 0.83rem;
    min-height: 18px;
    font-weight: 500;
}


/* ============================================================
   PAGE APPLICATION
   ============================================================ */
.app-page {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    background: var(--header-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--card-border);
    padding: 14px 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.app-logo {
    font-size: 1.6rem;
    color: var(--accent);
}

.app-header h2 {
    font-family: 'Syne', sans-serif;
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.header-date {
    font-size: 0.78rem;
    color: var(--text-muted);
    display: block;
    margin-top: 1px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.btn-icon {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    border: 1.5px solid var(--input-border);
    background: var(--input-bg);
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.25s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon:hover {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(91,33,182,0.12);
}

.btn-logout {
    padding: 9px 18px;
    border: 1.5px solid var(--accent);
    background: transparent;
    color: var(--accent);
    border-radius: 8px;
    font-family: 'DM Sans', sans-serif;
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s;
}

.btn-logout:hover {
    background: var(--accent);
    color: white;
}

/* Main */
.app-main {
    max-width: 680px;
    width: 100%;
    margin: 0 auto;
    padding: 28px 20px 60px;
    flex: 1;
}

/* Barre historique (Bonus 2) */
.history-bar {
    display: flex;
    gap: 20px;
    background: var(--history-bg);
    border-radius: 10px;
    padding: 10px 16px;
    margin-bottom: 20px;
    border: 1px solid var(--input-border);
    flex-wrap: wrap;
}

.history-bar span {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.stat-card {
    border-radius: 14px;
    padding: 18px 14px;
    text-align: center;
    border: 1px solid transparent;
}

.stat-total { background: var(--stat-total-bg); }
.stat-done  { background: var(--stat-done-bg); }
.stat-remaining { background: var(--stat-remaining-bg); }

.stat-number {
    display: block;
    font-family: 'Syne', sans-serif;
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 4px;
}

.stat-total .stat-number { color: var(--stat-total-color); }
.stat-done  .stat-number { color: var(--stat-done-color); }
.stat-remaining .stat-number { color: var(--stat-remaining-color); }

.stat-label {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    opacity: 0.7;
}

.stat-total .stat-label { color: var(--stat-total-color); }
.stat-done  .stat-label { color: var(--stat-done-color); }
.stat-remaining .stat-label { color: var(--stat-remaining-color); }

/* Carte d'ajout */
.add-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 22px 22px 20px;
    margin-bottom: 16px;
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
}

.add-card h3 {
    font-family: 'Syne', sans-serif;
    font-size: 0.88rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.07em;
    margin-bottom: 14px;
}

.add-row {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.add-row:last-child { margin-bottom: 0; }

.add-row input[type="text"] { flex: 2; min-width: 120px; }
.add-row select { flex: 1; min-width: 110px; }

.add-row button {
    padding: 12px 20px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 10px;
    font-family: 'Syne', sans-serif;
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    white-space: nowrap;
    transition: background 0.25s, transform 0.1s;
}

.add-row button:hover { background: var(--accent-hover); }
.add-row button:active { transform: scale(0.96); }

/* Recherche (Bonus 3) */
.search-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.search-bar input { flex: 2; min-width: 160px; }
.search-bar select { flex: 1; min-width: 140px; }

/* Liste des tâches */
.task-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.task-item {
    background: var(--task-bg);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 14px 16px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    animation: slideUp 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    transition: box-shadow 0.25s, transform 0.2s;
}

.task-item:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-1px);
}

.task-item.done {
    opacity: var(--done-opacity);
}

.task-item.urgent {
    border-left: 4px solid var(--red);
}

/* Checkbox personnalisée */
.task-check {
    width: 22px;
    height: 22px;
    min-width: 22px;
    border-radius: 6px;
    border: 2px solid var(--input-border);
    background: var(--input-bg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    margin-top: 2px;
    transition: all 0.2s;
}

.task-check.checked {
    background: var(--green);
    border-color: var(--green);
    color: white;
}

.task-body {
    flex: 1;
    min-width: 0;
}

.task-title {
    font-family: 'Syne', sans-serif;
    font-size: 0.98rem;
    font-weight: 600;
    color: var(--text-primary);
    word-break: break-word;
}

.task-item.done .task-title {
    text-decoration: line-through;
}

.task-desc {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-top: 3px;
    word-break: break-word;
}

.task-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 7px;
    flex-wrap: wrap;
}

.task-date {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.priority-tag {
    padding: 2px 9px;
    border-radius: 20px;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.03em;
}

.priority-Haute    { background: var(--tag-haute-bg);    color: var(--tag-haute-color); }
.priority-Moyenne  { background: var(--tag-moyenne-bg);  color: var(--tag-moyenne-color); }
.priority-Basse    { background: var(--tag-basse-bg);    color: var(--tag-basse-color); }

.urgent-tag {
    padding: 2px 9px;
    border-radius: 20px;
    font-size: 0.72rem;
    font-weight: 700;
    background: var(--tag-haute-bg);
    color: var(--tag-haute-color);
}

.task-actions {
    display: flex;
    gap: 6px;
    margin-top: 2px;
}

.task-actions button {
    width: 32px;
    height: 32px;
    border: 1.5px solid var(--input-border);
    background: var(--input-bg);
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.task-actions button:hover {
    border-color: var(--accent);
    background: var(--stat-total-bg);
}

.task-actions .btn-delete:hover {
    border-color: var(--red);
    background: var(--tag-haute-bg);
}

.empty-msg {
    text-align: center;
    color: var(--text-muted);
    padding: 40px 0;
    font-size: 0.95rem;
}


/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(10px); }
    to   { opacity: 1; transform: translateY(0); }
}


/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 480px) {
    .app-header { padding: 12px 16px; }
    .app-main   { padding: 20px 14px 50px; }
    .auth-card  { padding: 30px 22px; }
    .stats-grid { gap: 8px; }
    .stat-number { font-size: 1.6rem; }
}